Adhesion and proliferation of OCT-1 osteoblast-like cells on micro- and nano-scale topography structured poly(L-lactide).

PubMed

Wan, Yuqing; Wang, Yong; Liu, Zhimin; Qu, Xue; Han, Buxing; Bei, Jianzhong; Wang, Shenguo

2005-07-01

The impact of the surface topography of polylactone-type polymer on cell adhesion was to be concerned because the micro-scale texture of a surface can provide a significant effect on the adhesion behavior of cells on the surface. Especially for the application of tissue engineering scaffold, the pore size could have an influence on cell in-growth and subsequent proliferation. Micro-fabrication technology was used to generate specific topography to investigate the relationship between the cells and surface. In this study the pits-patterned surfaces of polystyrene (PS) film with diameters 2.2 and 0.45 microm were prepared by phase-separation, and the corresponding scale islands-patterned PLLA surface was prepared by a molding technique using the pits-patterned PS as a template. The adhesion and proliferation behavior of OCT-1 osteoblast-like cells morphology on the pits- and islands-patterned surface were characterized by SEM observation, cell attachment efficiency measurement and MTT assay. The results showed that the cell adhesion could be enhanced on PLLA and PS surface with nano-scale and micro-scale roughness compared to the smooth surfaces of the PLLA and PS. The OCT-1 osteoblast-like cells could grow along the surface with two different size islands of PLLA and grow inside the micro-scale pits of the PS. However, the proliferation of cells on the micro- and nano-scale patterned surface has not been enhanced compared with the controlled smooth surface.

Appearance of cell-adhesion factor in osteoblast proliferation and differentiation of apatite coating titanium by blast coating method.

PubMed

Umeda, Hirotsugu; Mano, Takamitsu; Harada, Koji; Tarannum, Ferdous; Ueyama, Yoshiya

2017-08-01

We have already reported that the apatite coating of titanium by the blast coating (BC) method could show a higher rate of bone contact from the early stages in vivo, when compared to the pure titanium (Ti) and the apatite coating of titanium by the flame spraying (FS) method. However, the detailed mechanism by which BC resulted in satisfactory bone contact is still unknown. In the present study, we investigated the importance of various factors including cell adhesion factor in osteoblast proliferation and differentiation that could affect the osteoconductivity of the BC disks. Cell proliferation assay revealed that Saos-2 could grow fastest on BC disks, and that a spectrophotometric method using a LabAssay TM ALP kit showed that ALP activity was increased in cells on BC disks compared to Ti disks and FS disks. In addition, higher expression of E-cadherin and Fibronectin was observed in cells on BC disks than Ti disks and FS disks by relative qPCR as well as Western blotting. These results suggested that the expression of cell-adhesion factors, proliferation and differentiation of osteoblast might be enhanced on BC disks, which might result higher osteoconductivity.

Osteoblast adhesion, migration, and proliferation variations on chemically patterned nanocrystalline diamond films evaluated by live-cell imaging.

PubMed

Broz, Antonin; Ukraintsev, Egor; Kromka, Alexander; Rezek, Bohuslav; Hubalek Kalbacova, Marie

2017-05-01

Cell fate modulation by adapting the surface of a biocompatible material is nowadays a challenge in implantology, tissue engineering as well as in construction of biosensors. Nanocrystalline diamond (NCD) thin films are considered promising in these fields due to their extraordinary physical and chemical properties and diverse ways in which they can be modified structurally and chemically. The initial cell distribution, the rate of cell adhesion, distance of cell migration and also the cell proliferation are influenced by the NCD surface termination. Here, we use real-time live-cell imaging to investigate the above-mentioned processes on oxidized NCD (NCD-O) and hydrogenated NCD (NCD-H) to elucidate cell preference to the NCD-O especially on surfaces with microscopic surface termination patterns. Cells adhere more slowly and migrate farther on NCD-H than on NCD-O. Cells seeded with a fetal bovine serum (FBS) supplement in the medium move across the surface prior to adhesion. In the absence of FBS, the cells adhere immediately, but still exhibit different migration and proliferation on NCD-O/H regions. We discuss the impact of these effects on the formation of cell arrays on micropatterned NCD. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1469-1478, 2017. © 2017 Wiley Periodicals, Inc.

Nano-hydroxyapatite-coated metal-ceramic composite of iron-tricalcium phosphate: Improving the surface wettability, adhesion and proliferation of mesenchymal stem cells in vitro.

PubMed

Surmeneva, Maria A; Kleinhans, Claudia; Vacun, Gabriele; Kluger, Petra Juliane; Schönhaar, Veronika; Müller, Michaela; Hein, Sebastian Boris; Wittmar, Alexandra; Ulbricht, Mathias; Prymak, Oleg; Oehr, Christian; Surmenev, Roman A

2015-11-01

Thin radio-frequency magnetron sputter deposited nano-hydroxyapatite (HA) films were prepared on the surface of a Fe-tricalcium phosphate (Fe-TCP) bioceramic composite, which was obtained using a conventional powder injection moulding technique. The obtained nano-hydroxyapatite coated Fe-TCP biocomposites (nano-HA-Fe-TCP) were studied with respect to their chemical and phase composition, surface morphology, water contact angle, surface free energy and hysteresis. The deposition process resulted in a homogeneous, single-phase HA coating. The ability of the surface to support adhesion and the proliferation of human mesenchymal stem cells (hMSCs) was studied using biological short-term tests in vitro. The surface of the uncoated Fe-TCP bioceramic composite showed an initial cell attachment after 24h of seeding, but adhesion, proliferation and growth did not persist during 14 days of culture. However, the HA-Fe-TCP surfaces allowed cell adhesion, and proliferation during 14 days. The deposition of the nano-HA films on the Fe-TCP surface resulted in higher surface energy, improved hydrophilicity and biocompatibility compared with the surface of the uncoated Fe-TCP. Furthermore, it is suggested that an increase in the polar component of the surface energy was responsible for the enhanced cell adhesion and proliferation in the case of the nano-HA-Fe-TCP biocomposites. Copyright © 2015 Elsevier B.V. All rights reserved.

Surface modification of starch based blends using potassium permanganate-nitric acid system and its effect on the adhesion and proliferation of osteoblast-like cells.

PubMed

Pashkuleva, I; Marques, A P; Vaz, F; Reis, R L

2005-01-01

The surface modification of three starch based polymeric biomaterials, using a KMnO4/HNO3 oxidizing system, and the effect of that modification on the osteoblastic cell adhesion has been investigated. The rationale of this work is as follows--starch based polymers have been proposed for use as tissue engineering scaffolds in several publications. It is known that in biodegradable systems it is quite difficult to have both cell adhesion and proliferation. Starch based polymers have shown to perform better than poly-lactic acid based materials but there is still room for improvement. This particular work is aimed at enhancing cell adhesion and proliferation on the surface of several starch based polymer blends that are being proposed as tissue engineering scaffolds. The surface of the polymeric biomaterials was chemically modified using a KMnO4/HNO3 system. This treatment resulted in more hydrophilic surfaces, which was confirmed by contact angle measurements. The effect of the treatment on the bioactivity of the surface modified biomaterials was also studied. The bioactivity tests, performed in simulated body fluid after biomimetic coating, showed that a dense film of calcium phosphate was formed after 30 days. Finally, human osteoblast-like cells were cultured on unmodified (control) and modified materials in order to observe the effect of the presence of higher numbers of polar groups on the adhesion and proliferation of those cells. Two of the modified polymers presented changes in the adhesion behavior and a significant increase in the proliferation rate kinetics when compared to the unmodified controls.

Influence of Partial O₂ Pressure on the Adhesion, Proliferation, and Osteogenic Differentiation of Human Dental Pulp Stem Cells on β-Tricalcium Phosphate Scaffold.

PubMed

Viña-Almunia, Jose; Mas-Bargues, Cristina; Borras, Consuelo; Gambini, Juan; El Alami, Marya; Sanz-Ros, Jorge; Peñarrocha, Miguel; Vina, Jose

To analyze, in vitro, the influence of O₂ pressure on the adhesion, proliferation, and osteogenic differentiation of human dental pulp stem cells (DPSC) on β-tricalcium phosphate (β-TCP) scaffold. DPSC, positive for the molecular markers CD133, Oct4, Nestin, Stro-1, and CD34, and negative for CD45, were isolated from extracted third molars. Experiments were started by seeding 200,000 cells on β-TCP cultured under 3% or 21% O₂ pressure. No osteogenic medium was used. Eight different cultures were performed at each time point under each O₂ pressure condition. Cell adhesion, proliferation, and differentiation over the biomaterial were evaluated at 7, 13, 18, and 23 days of culture. Cell adhesion was determined by light microscopy, proliferation by DNA quantification, and osteogenic differentiation by alkaline phosphatase (ALP) activity analysis. DPSC adhered to β-TCP with both O₂ conditions. Cell proliferation was found from day 7 of culture. Higher values were recorded at 3% O₂ in each time point. Statistically significant differences were recorded at 23 days of culture (P = .033). ALP activity was not detectable at 7 days. There was, however, an increase in ALP activity over time in both groups. At 13, 18, and 23 days of culture, higher ALP activity was recorded under 3% O₂ pressure. Statistical differences were found at day 23 (P = .014). DPSC display capacity of adhering to β-TCP under 3% or 21% O₂ pressure conditions. Cell proliferation on β-TCP phosphate is significantly higher at 3% than at 21% O₂ pressure, the most frequently used O₂ tension. β-TCP can itself promote osteogenic differentiation of DPSC and is enhanced under 3% O₂ compared with 21%.

Graphene coating on the surface of CoCrMo alloy enhances the adhesion and proliferation of bone marrow mesenchymal stem cells.

PubMed

Zhang, Qi; Li, Kewen; Yan, Jinhong; Wang, Zhuo; Wu, Qi; Bi, Long; Yang, Min; Han, Yisheng

2018-03-18

The objective was to investigate whether a graphene coating could improve the surface bioactivity of a cobalt-chromium-molybdenum-based alloy (CoCrMo). Graphene was produced by chemical vapor deposition and transferred to the surface of the CoCrMo alloy using an improved wet transfer approach. The morphology of the samples was observed, and the adhesion force and stabilization of graphene coating were analyzed by a nanoscratch test and ultrasonication test. In an in vitro study, the adhesion and proliferation of bone marrow mesenchymal stem cells (BMSCs) cultured on the samples were quantified via an Alamar Blue assay and cell counting kit-8 (CCK-8) assay. The results showed that it is feasible to apply graphene to modify the surface of a CoCrMo alloy, and the enhancement of the adhesion and proliferation of BMSCs was also shown in the present study. In conclusion, graphene exhibits considerable potential for enhancing the surface bioactivity of CoCrMo alloy. Copyright © 2018 Elsevier Inc. All rights reserved.

Protopine inhibits heterotypic cell adhesion in MDA-MB-231 cells through down-regulation of multi-adhesive factors.

PubMed

He, Kai; Gao, Jian-Li

2014-01-01

A Chinese herb Corydalis yanhusuo W.T. Wang that showed anticancer and anti-angiogenesis effects in our previous studies was presented for further studies. In the present study, we studied the anticancer proliferation and adhesion effects of five alkaloids which were isolated from Corydalis yanhusuo. MTT dose response curves, cell migration assay, cell invasion assay, as well as three types of cell adhesive assay were performed on MDA-MB-231 human breast cancer cells. The mechanism of the compounds on inhibiting heterotypic cell adhesion were further explored by determining the expression of epidermal growth factor receptor (EGFR), Intercellular adhesion molecule 1 (ICAM-1), αv-integrin, β1-integrin and β5-integrin by western blotting assay. In five tested alkaloids, only protopine exhibited anti-adhesive and anti-invasion effects in MDA-MB-231 cells, which contributed to the anti-metastasis effect of Corydalis yanhusuo. The results showed that after treatment with protopine for 90 min, the expression of EGFR, ICAM-1, αv-integrin, β1-integrin and β5-integrin were remarkably reduced. The present results suggest that protopine seems to inhibit the heterotypic cell adhesion between MDA-MB-231 cells, and human umbilical vein endothelial cells by changing the expression of adhesive factors.

Cell-contact-dependent activation of CD4+ T cells by adhesion molecules on synovial fibroblasts.

PubMed

Mori, Masato; Hashimoto, Motomu; Matsuo, Takashi; Fujii, Takao; Furu, Moritoshi; Ito, Hiromu; Yoshitomi, Hiroyuki; Hirose, Jun; Ito, Yoshinaga; Akizuki, Shuji; Nakashima, Ran; Imura, Yoshitaka; Yukawa, Naoichiro; Yoshifuji, Hajime; Ohmura, Koichiro; Mimori, Tsuneyo

2017-05-01

To determine how cell-cell contact with synovial fibroblasts (SF) influence on the proliferation and cytokine production of CD4 +  T cells. Naïve CD4 +  T cells were cultured with SF from rheumatoid arthritis patients, stimulated by anti-CD3/28 antibody, and CD4 +  T cell proliferation and IFN-γ/IL-17 production were analyzed. To study the role of adhesion molecules, cell contact was blocked by transwell plate or anti-intracellular adhesion molecule-1 (ICAM-1)/vascular cell adhesion molecule-1(VCAM-1) antibody. To study the direct role of adhesion molecules for CD4 +  T cells, CD161 +  or CD161 - naïve CD4 +  T cells were stimulated on plastic plates coated by recombinant ICAM-1 or VCAM-1, and the source of IFN-γ/IL-17 were analyzed. SF enhanced naïve CD4 +  T cell proliferation and IFN-γ/IL-17 production in cell-contact and in part ICAM-1-/VCAM-1-dependent manner. Plate-coated ICAM-1 and VCAM-1 enhanced naïve CD4 +  T cell proliferation and IFN-γ production, while VCAM-1 efficiently promoting IL-17 production. CD161 +  naïve T cells upregulating LFA-1 and VLA-4 were the major source of IFN-γ/IL-17 upon interaction with ICAM-1/VCAM-1. CD4 +  T cells rapidly expand and secrete IFN-γ/IL-17 upon cell-contact with SF via adhesion molecules. Interfering with ICAM-1-/VCAM-1 may be beneficial for inhibiting RA synovitis.

[Effects of sintered bone modified with surface mineralization/P24 peptide composite biomaterial on the adhesion, proliferation and osteodifferentiation of MC3T3-E1 cells].

PubMed

Li, Jingfeng; Zheng, Qixin; Guo, Xiaodong; Chen, Liaobin

2014-10-01

In the present research, the effects of sintered bone modified with surface mineralization/P24 peptide composite biomaterials on the adhesion, proliferation and osteodifferentiation of MC3T3-E1 cells were investigated. The experiments were divided into three groups due to biomaterials used: Group A (composite materials of sintered bone modified with surface mineralization and P24, a peptide of bone morphogenetic protein-2); Group B (sintered bone modified with surface mineralization) and Group C (sintered bone only). The three groups were observed by scanning electron microscopy (SEM) before the experiments, respectively. Then MC3T3-E1 cells were cultured on the surfaces of the three kinds of material, respectively. The cell adhesion rate was assessed by precipitation method. The proliferative ability of MC3T3-E1 cells were measured with MTT assay. And the ALP staining and measurement of alkaline phosphatase (ALP) activity were performed to assess the differentiation of cells into osteoblasts. The SEM results showed that the materials in the three groups retained the natural pore structure and the pore sizes were in the range between 200-850 μm. The adhesive ratio measurements and MTT assay suggested that adhesion and proliferation of MC3T3-E1 cells in Group A were much higher than those in Group B and Group C (P < 0.05). The ALP staining and ALP activity of MC3T3-E1 cells in Group A were significantly higher than those in Group B and Group C (P < 0.05). The sintered bone modified with surface mineralization/P24 composite material was confirmed to improve the adhesion rate and proliferation and osteodifferentiation of MC3T3-E1 cells, and maintained their morphology.

Influence of different modifications of a calcium phosphate bone cement on adhesion, proliferation, and osteogenic differentiation of human bone marrow stromal cells.

PubMed

Vater, Corina; Lode, Anja; Bernhardt, Anne; Reinstorf, Antje; Heinemann, Christiane; Gelinsky, Michael

2010-03-15

Collagen and noncollagenous proteins of the extracellular bone matrix are able to stimulate bone cell activities and bone healing. The modification of calcium phosphate bone cements used as temporary bone replacement materials with these proteins seems to be a promising approach to accelerate new bone formation. In this study, we investigated adhesion, proliferation, and osteogenic differentiation of human bone marrow stromal cells (hBMSC) on Biocement D/collagen composites which have been modified with osteocalcin and O-phospho-L-serine. Modification with osteocalcin was carried out by its addition to the cement precursor before setting as well as by functionalization of the cement samples after setting and sterilization. hBMSC were cultured on these samples for 28 days with and without osteogenic supplements. We found a positive impact especially of the phosphoserine-modifications but also of both osteocalcin-modifications on differentiation of hBMSC indicated by higher expression of the osteoblastic markers matrix metalloproteinase-13 and bone sialo protein II. For hBMSC cultured on phosphoserine-containing composites, an increased proliferation has been observed. However, in case of the osteocalcin-modified samples, only osteocalcin adsorbed after setting and sterilization of the cement samples was able to promote initial adhesion and proliferation of hBMSC. The addition of osteocalcin before setting results in a finer microstructure but the biological activity of osteocalcin might be impaired due to the sterilization process. Thus, our data indicate that the initial adhesion and proliferation of hBMSC is enhanced rather by the biological activity of osteocalcin than by the finer microstructure. (c) 2009 Wiley Periodicals, Inc.

Factors Released from Endothelial Cells Exposed to Flow Impact Adhesion, Proliferation, and Fate Choice in the Adult Neural Stem Cell Lineage.

PubMed

Dumont, Courtney M; Piselli, Jennifer M; Kazi, Nadeem; Bowman, Evan; Li, Guoyun; Linhardt, Robert J; Temple, Sally; Dai, Guohao; Thompson, Deanna M

2017-08-15

The microvasculature within the neural stem cell (NSC) niche promotes self-renewal and regulates lineage progression. Previous work identified endothelial-produced soluble factors as key regulators of neural progenitor cell (NPC) fate and proliferation; however, endothelial cells (ECs) are sensitive to local hemodynamics, and the effect of this key physiological process has not been defined. In this study, we evaluated adult mouse NPC response to soluble factors isolated from static or dynamic (flow) EC cultures. Endothelial factors generated under dynamic conditions significantly increased neuronal differentiation, while those released under static conditions stimulated oligodendrocyte differentiation. Flow increases EC release of neurogenic factors and of heparin sulfate glycosaminoglycans that increase their bioactivity, likely underlying the enhanced neuronal differentiation. Additionally, endothelial factors, especially from static conditions, promoted adherent growth. Together, our data suggest that blood flow may impact proliferation, adhesion, and the neuron-glial fate choice of adult NPCs, with implications for diseases and aging that reduce flow.

Osteoblastlike cell adhesion on titanium surfaces modified by plasma nitriding.

PubMed

da Silva, Jose Sandro Pereira; Amico, Sandro Campos; Rodrigues, Almir Olegario Neves; Barboza, Carlos Augusto Galvao; Alves, Clodomiro; Croci, Alberto Tesconi

2011-01-01

The aim of this study was to evaluate the characteristics of various titanium surfaces modified by cold plasma nitriding in terms of adhesion and proliferation of rat osteoblastlike cells. Samples of grade 2 titanium were subjected to three different surface modification processes: polishing, nitriding by plasma direct current, and nitriding by cathodic cage discharge. To evaluate the effect of the surface treatment on the cellular response, the adhesion and proliferation of osteoblastlike cells (MC3T3) were quantified and the results were analyzed by Kruskal-Wallis and Friedman statistical tests. Cellular morphology was observed by scanning electron microscopy. There was more MC3T3 cell attachment on the rougher surfaces produced by cathodic cage discharge compared with polished samples (P < .05). Plasma nitriding improves titanium surface roughness and wettability, leading to osteoblastlike cell adhesion.

Adhesion Molecule Expression and Function of Primary Endothelial Cells in Benign and Malignant Tissues Correlates with Proliferation

PubMed Central

Sievert, Wolfgang; Tapio, Soile; Breuninger, Stephanie; Gaipl, Udo; Andratschke, Nicolaus; Trott, Klaus-Rüdiger; Multhoff, Gabriele

2014-01-01

Background Comparative analysis of the cellular biology of the microvasculature in different tissues requires the availability of viable primary endothelial cells (ECs). This study describes a novel method to isolate primary ECs from healthy organs, repair blastemas and tumors as examples of non-proliferating and proliferating benign and malignant tissues and their functional characterization. Methodology/Principal Findings Single cell suspensions from hearts, lungs, repair blastemas and tumors were incubated consecutively with an anti-CD31 antibody and magnetic micro-beads, coupled to a derivative of biotin and streptavidin, respectively. Following magnetic bead separation, CD31-positive ECs were released by biotin-streptavidin competition. In the absence of micro-beads, ECs became adherent to plastic surfaces. ECs from proliferating repair blastemas and tumors were larger and exhibited higher expression densities of CD31, CD105 and CD102 compared to those from non-proliferating normal tissues such as heart and lung. The expression density of CD34 was particularly high in tumor-derived ECs, and that of CD54 and CD144 in ECs of repair blastemas. Functionally, ECs of non-proliferating and proliferating tissues differed in their capacity to form tubes in matrigel and to align under flow conditions. Conclusions/Significance This method provides a powerful tool to generate high yields of viable, primary ECs of different origins. The results suggest that an altered expression of adhesion molecules on ECs in proliferating tissues contribute to loss of EC function that might cause a chaotic tumor vasculature. PMID:24632811

Down-regulation of CD19 expression inhibits proliferation, adhesion, migration and invasion and promotes apoptosis and the efficacy of chemotherapeutic agents and imatinib in SUP-B15 cells.

PubMed

Wu, Junqing; Liang, Bin; Qian, Yan; Tang, Liyuan; Xing, Chongyun; Zhuang, Qiang; Shen, Zhijian; Jiang, Songfu; Yu, Kang; Feng, Jianhua

2018-05-29

The survival rate of childhood acute lymphoblastic leukemia (ALL) has increased while that of Philadelphia-positive (Ph+) ALL remains low. CD19 is a B-cell specific molecule related to the survival and proliferation of normal B cells. However, there is little information available on the effects of CD19 on the biological behavior of Ph+ ALL cells. In this study, we explored a lentiviral vector-mediated short hairpin RNA (shRNA) expression vector to stably reduce CD19 expression in Ph+ ALL cell line SUP-B15 cells and investigated the effects of CD19 downregulation on cell proliferation, apoptosis, drug sensitivity, cell adhesion, cell migration and cell invasion in vitro. CD19 mRNA and protein expression levels were inhibited significantly by CD19 shRNA. Down-regulation of CD19 could inhibit cell proliferation, adhesion, migration and invasion, and increase cell apoptosis and the efficacy of chemotherapeutic agents and imatinib in SUP-B15 cells. Moreover, we found that down-regulation of CD19 expression inhibits cell proliferation and induces apoptosis in SUP-B15 cells in a p53-dependent manner. Taken together, our results suggest that lentiviral vector-mediated RNA interference of CD19 gene may be a promising strategy in the treatment of Ph+ ALL. This article is protected by copyright. All rights reserved.

[Effects of basic fibroblast growth factor and vascular endothelial growth factor on the proliferation, migration and adhesion of human periodontal ligament stem cells in vitro].

PubMed

Zhang, Rong; Zhang, Mian; Li, Cheng-hua; Wang, Peng-cheng; Chen, Fang; Wang, Qin-tao

2013-05-01

To evaluate the effects of basic fibroblast growth factor (FGF-2) and vascular endothelial growth factor (VEGF) on the proliferation, migration, and adhesion of human periodontal ligament stem cells (PDLSC) in vitro. Human PDLSC were cultured in vitro using tissue culture method.The cells were cultured and incubated with various concentrations of FGF-2 and VEGF [A:α-MEM with 2% fetal bovine serum (FBS) (control 1); B:A supplemented with 20 µg/L FGF-2; C:A supplemented with 10 µg/L VEGF; D:A supplemented with 20 µg/L FGF-2 and 10 µg/L VEGF; E:α-MEM with 10% FBS (control 2); F:E supplemented with 20 µg/L FGF-2; G:E supplemented with 10 µg/L VEGF; H:E supplemented with 20 µg/L FGF-2 and 10 µg/L VEGF]. Soluble tetrazolium salts assay was used to evaluate the proliferative capacity on the 1st, 3rd, 5th and 7th d. Then the groups were changed according to result of the proliferation assay (control:α-MEM with 2% FBS; FGF-2 group:control supplemented with 20 µg/L FGF-2; VEGF:control supplemented with 10 µg/L VEGF; Combination group:control supplemented with 20 µg/L FGF-2 and 10 µg/L VEGF). The cell cycle, migration and adhesion capacities were evaluated using flow cytometer, soluble tetrazolium salts assay, cell adhesion assay and scratch wound-healing motility assay. In 2% volume fraction serum containing medium, FGF-2 and VEGF did not stimulate the cell proliferation. However, in 10% serum condition, in groups treated with FGF-2 for 3,5 or 7 d, the A value was (1.22 ± 0.17, 2.15 ± 0.19, 2.72 ± 0.11) respectively, which were significantly higher than that in the control group (0.76 ± 0.16, 1.25 ± 0.06, 1.64 ± 0.09) (P < 0.01) while lower than that in the group treated with FGF-2 and VEGF in combination on the 5 th and 7 th d (2.46 ± 0.17, 3.18 ± 0.27) ( P < 0.05). The A value in the VEGF group on the 5 th and 7 th d is higher than the control group while lower than the FGF-2 group (1.66 ± 0.05, 2.13 ± 0.13) (P < 0.05). Flow cytometer showed that

Simulation of proliferation and differentiation of cells in a stem-cell niche

NASA Astrophysics Data System (ADS)

Zhdanov, Vladimir P.

2008-10-01

Stem-cell niches represent microscopic compartments formed of environmental cells that nurture stem cells and enable them to maintain tissue homeostasis. The spatio-temporal kinetics of proliferation and differentiation of cells in such niches depend on the specifics of the niche structure and on adhesion and communication between cells and may also be influenced by spatial constraints on cell division. We propose a generic lattice model, taking all these factors into account, and systematically illustrate their role. The model is motivated by the experimental data available for the niches located in the subventricular zone of adult mammalian brain. The general conclusions drawn from our Monte Carlo simulations are applicable to other niches as well. One of our main findings is that the kinetics under consideration are highly stochastic due to a relatively small number of cells proliferating and differentiating in a niche and the autocatalytic character of the symmetric cell division. In particular, the kinetics exhibit huge stochastic bursts especially if the adhesion between cells is taken into account. In addition, the results obtained show that despite the small number of cells present in stem-cell niches, their arrangement can be predetermined to appreciable extent provided that the adhesion of different cells is different so that they tend to segregate.

Tuning cell adhesion by direct nanostructuring silicon into cell repulsive/adhesive patterns

DOE Office of Scientific and Technical Information (OSTI.GOV)

Premnath, Priyatha, E-mail: priyatha.premnath@ryerson.ca; Tavangar, Amirhossein, E-mail: atavanga@ryerson.ca; Tan, Bo, E-mail: tanbo@ryerson.ca

2015-09-10

Developing platforms that allow tuning cell functionality through incorporating physical, chemical, or mechanical cues onto the material surfaces is one of the key challenges in research in the field of biomaterials. In this respect, various approaches have been proposed and numerous structures have been developed on a variety of materials. Most of these approaches, however, demand a multistep process or post-chemical treatment. Therefore, a simple approach would be desirable to develop bio-functionalized platforms for effectively modulating cell adhesion and consequently programming cell functionality without requiring any chemical or biological surface treatment. This study introduces a versatile yet simple laser approachmore » to structure silicon (Si) chips into cytophobic/cytophilic patterns in order to modulate cell adhesion and proliferation. These patterns are fabricated on platforms through direct laser processing of Si substrates, which renders a desired computer-generated configuration into patterns. We investigate the morphology, chemistry, and wettability of the platform surfaces. Subsequently, we study the functionality of the fabricated platforms on modulating cervical cancer cells (HeLa) behaviour. The results from in vitro studies suggest that the nanostructures efficiently repel HeLa cells and drive them to migrate onto untreated sites. The study of the morphology of the cells reveals that cells evade the cytophobic area by bending and changing direction. Additionally, cell patterning, cell directionality, cell channelling, and cell trapping are achieved by developing different platforms with specific patterns. The flexibility and controllability of this approach to effectively structure Si substrates to cell-repulsive and cell-adhesive patterns offer perceptible outlook for developing bio-functionalized platforms for a variety of biomedical devices. Moreover, this approach could pave the way for developing anti-cancer platforms that selectively

Polymeric vs hydroxyapatite-based scaffolds on dental pulp stem cell proliferation and differentiation

PubMed Central

Khojasteh, Arash; Motamedian, Saeed Reza; Rad, Maryam Rezai; Shahriari, Mehrnoosh Hasan; Nadjmi, Nasser

2015-01-01

AIM: To evaluate adhesion, proliferation and differentiation of human dental pulp stem cells (hDPSCs) on four commercially available scaffold biomaterials. METHODS: hDPSCs were isolated from human dental pulp tissues of extracted wisdom teeth and established in stem cell growth medium. hDPSCs at passage 3-5 were seeded on four commercially available scaffold biomaterials, SureOss (Allograft), Cerabone (Xenograft), PLLA (Synthetic), and OSTEON II Collagen (Composite), for 7 and 14 d in osteogenic medium. Cell adhesion and morphology to the scaffolds were evaluated by scanning electron microscopy (SEM). Cell proliferation and differentiation into osteogenic lineage were evaluated using DNA counting and alkaline phosphatase (ALP) activity assay, respectively. RESULTS: All scaffold biomaterials except SureOss (Allograft) supported hDPSC adhesion, proliferation and differentiation. hDPSCs seeded on PLLA (Synthetic) scaffold showed the highest cell proliferation and attachment as indicated with both SEM and DNA counting assay. Evaluating the osteogenic differentiation capability of hDPSCs on different scaffold biomaterials with ALP activity assay showed high level of ALP activity on cells cultured on PLLA (Synthetic) and OSTEON II Collagen (Composite) scaffolds. SEM micrographs also showed that in the presence of Cerabone (Xenograft) and OSTEON II Collagen (Composite) scaffolds, the hDPSCs demonstrated the fibroblastic phenotype with several cytoplasmic extension, while the cells on PLLA scaffold showed the osteoblastic-like morphology, round-like shape. CONCLUSION: PLLA scaffold supports adhesion, proliferation and osteogenic differentiation of hDPSCs. Hence, it may be useful in combination with hDPSCs for cell-based reconstructive therapy. PMID:26640621

ETV5 transcription factor is overexpressed in ovarian cancer and regulates cell adhesion in ovarian cancer cells.

PubMed

Llauradó, Marta; Abal, Miguel; Castellví, Josep; Cabrera, Sílvia; Gil-Moreno, Antonio; Pérez-Benavente, Asumpció; Colás, Eva; Doll, Andreas; Dolcet, Xavier; Matias-Guiu, Xavier; Vazquez-Levin, Mónica; Reventós, Jaume; Ruiz, Anna

2012-04-01

Epithelial ovarian cancer is the most lethal gynecological malignancy and the fifth leading cause of cancer deaths in women in the Western world. ETS transcription factors are known to act as positive or negative regulators of the expression of genes that are involved in various biological processes, including those that control cellular proliferation, differentiation, apoptosis, tissue remodeling, angiogenesis and transformation. ETV5 belongs to the PEA3 subfamily. PEA3 subfamily members are able to activate the transcription of proteases, matrix metalloproteinases and tissue inhibitor of metalloproteases, which is central to both tumor invasion and angiogenesis. Here, we examined the role of the ETV5 transcription factor in epithelial ovarian cancer and we found ETV5 was upregulated in ovarian tumor samples compared to ovarian tissue controls. The in vitro inhibition of ETV5 decreased cell proliferation in serum-deprived conditions, induced EMT and cell migration and decreased cell adhesion to extracellular matrix components. ETV5 inhibition also decreased cell-cell adhesion and induced apoptosis in anchorage-independent conditions. Accordingly, upregulation of ETV5 induced the expression of cell adhesion molecules and enhanced cell survival in a spheroid model. Our findings suggest that the overexpression of ETV5 detected in ovarian cancer cells may contribute to ovarian tumor progression through the ability of ETV5 to enhance proliferation of ovarian cancer cells. In addition, upregulation of ETV5 would play a role in ovarian cancer cell dissemination and metastasis into the peritoneal cavity by protecting ovarian cancer cells from apoptosis and by increasing the adhesion of ovarian cancer cells to the peritoneal wall through the regulation of cell adhesion molecules. Copyright © 2011 UICC.

In vitro adhesion of fibroblastic cells to titanium alloy discs treated with sodium hydroxide.

PubMed

Al Mustafa, Maisa; Agis, Hermann; Müller, Heinz-Dieter; Watzek, Georg; Gruber, Reinhard

2015-01-01

Adhesion of osteogenic cells on titanium surfaces is a prerequisite for osseointegration. Alkali treatment can increase the hydrophilicity of titanium implant surfaces, thereby supporting the adhesion of blood components. However, it is unclear if alkali treatment also supports the adhesion of cells with a fibroblastic morphology to titanium. Here, we have used a titanium alloy (Ti-6AL-4V) processed by alkali treatment to demonstrate the impact of hydrophilicity on the adhesion of primary human gingival fibroblast and bone cells. Also included were the osteosarcoma and fibroblastoma cell lines, MG63 and L929, respectively. Cell adhesion was determined by scanning electron microscopy. We also measured viability, proliferation, and protein synthesis of the adherent cells. Alkali treatment increased the adhesion of gingival fibroblasts, bone cells, and the two cell lines when seeded onto the titanium alloy surface for 1 h. At 3 h, no significant changes in cell adhesion were observed. Cells grown for 1 day on the titanium alloy surfaces processed by alkali treatment behave similarly to untreated controls with regard to viability, proliferation, and protein synthesis. Based on these preliminary In vitro findings, we conclude that alkali treatment can support the early adhesion of cells with fibroblastic characteristics to a titanium alloy surface. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of molecular weight and concentration of hyaluronan on cell proliferation and osteogenic differentiation in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Ningbo, E-mail: curl-zhao@163.com; Wang, Xin, E-mail: 394041230@qq.com; Qin, Lei, E-mail: qinlei30@126.com

Hyaluronan (HA), the simplest glycosaminoglycan and a major component of the extracellular matrix, exists in various tissues. It is involved in some critical biological procedures, including cellular signaling, cell adhesion and proliferation, and cell differentiation. The effect of molecular weight (MW) and concentration of HA on cell proliferation and differentiation was controversial. In this study, we investigated the effect of MW and concentration of HA on the proliferation and osteogenic differentiation of rabbit bone marrow-derived stem cells in vitro. Results showed that high MW HA decreased the cell adhesion rate in a concentration-dependant manner. The cell adhesion rate was decreased bymore » increasing MW of HA. Cell proliferation was significantly enhanced by low MW HA (P < 0.05). The factorial analysis indicated that MW and concentration had an interactive effect on the cell adhesion rate and cell proliferation (P < 0.05). High MW HA increased the mRNA expressions of ALP, RUNX-2 and OCN. The higher the MW was, the higher the mRNA expressions were. The factorial analysis indicated that MW and concentration had an interactive effect on ALP mRNA expression (P < 0.05). HA of higher MW and higher concentration promoted bone formation. These findings provide some useful information in understanding the mechanism underlying the effect of MW and concentration of HA on cell proliferation and differentiation. - Highlights: • Effect of hyaluronan on cell proliferation and differentiation is evaluated in vitro. • Hyaluronan of low molecular weight increases cell proliferation. • Hyaluronan of high molecular weight promotes cell osteogenic differentiation. • Molecular weight and concentration of hyaluronan show interactive effect.« less

Porous titania surfaces on titanium with hierarchical macro- and mesoporosities for enhancing cell adhesion, proliferation and mineralization.

PubMed

Han, Guang; Müller, Werner E G; Wang, Xiaohong; Lilja, Louise; Shen, Zhijian

2015-02-01

Titanium received a macroporous titania surface layer by anodization, which contains open pores with average pore diameter around 5 μm. An additional mesoporous titania top layer following the contour of the macropores, of 100-200 nm thickness and with a pore diameter of 10nm, was formed by using the evaporation-induced self-assembly (EISA) method with titanium (IV) tetraethoxide as the precursor. A coherent laminar titania surface layer was thus obtained, creating a hierarchical macro- and mesoporous surface that was characterized by high-resolution electron microscopy. The interfacial bonding between the surface layers and the titanium matrix was characterized by the scratch test that confirmed a stable and strong bonding of titania surface layers on titanium. The wettability to water and the effects on the osteosarcoma cell line (SaOS-2) proliferation and mineralization of the formed titania surface layers were studied systematically by cell culture and scanning electron microscopy. The results proved that the porous titania surface with hierarchical macro- and mesoporosities was hydrophilic that significantly promoted cell attachment and spreading. A synergistic role of the hierarchical macro- and mesoporosities was revealed in terms of enhancing cell adhesion, proliferation and mineralization, compared with the titania surface with solo scale topography. Copyright © 2014 Elsevier B.V. All rights reserved.

Enhanced human osteoblast cell adhesion and proliferation on 316 LS stainless steel by means of CO2 laser surface treatment.

PubMed

Hao, L; Lawrence, J; Phua, Y F; Chian, K S; Lim, G C; Zheng, H Y

2005-04-01

An effective and novel technique for improving the biocompatibility of a biograde 316 LS stainless steel through the application of CO(2) laser treatment to modify the surface properties of the material is described herein. Different surface properties, such as surface roughness, surface oxygen content, and surface energy for CO(2) laser-treated 316 LS stainless steel, untreated, and mechanically roughened samples were analyzed, and their effects on the wettability characteristics of the material were studied. It was found that modification of the wettability characteristics of the 316 LS stainless steel following CO(2) laser treatment was achieved. This improvement was identified as being mainly due to the change in the polar component of the surface energy. One-day cell adhesion tests showed that cells not only adhered and spread better, but also grew faster on the CO(2) laser-treated sample than on either the untreated or mechanically roughened sample. Further, compared with the untreated sample, MTT cell proliferation analysis revealed that the mechanically roughed surface resulted in a slight enhancement, and CO(2) laser treatment brought about a significant increase in cell proliferation. An increase in the wettability of the 316 LS stainless steel was observed to positively correlate with the cell proliferation. (c) 2004 Wiley Periodicals, Inc.

Low Doses of Curcuma longa Modulates Cell Migration and Cell-Cell Adhesion.

PubMed

de Campos, Paloma Santos; Matte, Bibiana Franzen; Diel, Leonardo Francisco; Jesus, Luciano Henrique; Bernardi, Lisiane; Alves, Alessandro Menna; Rados, Pantelis Varvaki; Lamers, Marcelo Lazzaron

2017-09-01

Cell invasion and metastasis are involved in clinical failures in cancer treatment, and both events require the acquisition of a migratory behavior by tumor cells. Curcumin is a promising natural product with anti-proliferative activity, but its effects on cell migration are still unclear. We evaluated the effects of curcumin on the proliferation, apoptosis, migration, and cell-cell adhesion of keratinocyte, oral squamous cell carcinoma (OSCC), and fibroblast cell lines, as well as in a xenograft model of OSCC. Curcumin (2 μM) decreased cell proliferation in cell lines with mesenchymal characteristics, while cell death was detected only at 50 μM. We observed that highly migratory cells showed a decrease on migration speed and directionality when treated with 2 or 5 μM of curcumin (50% and 40%, respectively, p < 0.05). Using spheroids, we observed that curcumin dose dependently decreased cell-cell adhesion, especially on tumor-derived spheroids. Also, in a xenograft model with patient-derived OSCC cells, the administration of curcumin decreased tumor growth and aggressiveness when compared with untreated tumors, indicating the potential antitumor effect in oral cancer. These results suggest that lower doses of curcumin can influence several steps involved in tumorigenesis, including migration properties, suggesting a possible use in cancer therapy. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Cell adhesion and proliferation on poly(tetrafluoroethylene) with plasma-metal and plasma-metal-carbon interfaces

NASA Astrophysics Data System (ADS)

Reznickova, Alena; Kvitek, Ondrej; Kolarova, Katerina; Smejkalova, Zuzana; Svorcik, Vaclav

2017-06-01

The aim of this article is to investigate the effect of the interface between plasma activated, gold and carbon coated poly(tetrafluoroethylene) (PTFE) on in vitro adhesion and spreading of mouse fibroblasts (L929). Surface properties of pristine and modified PTFE were studied by several experimental techniques. The thickness of a deposited gold film is an increasing function of the sputtering time, conversely thickness of carbon layer decreases with increasing distance between carbon source and the substrate. Because all the used surface modification techniques take place in inert Ar plasma, oxidized degradation products are formed on the PTFE surface, which affects wettability of the polymer surface. Cytocompatibility tests indicate that on samples with Au/C interface, the cells accumulate on the part of sample with evaporated carbon. Number of L929 cells proliferated on the studied samples is comparable to tissue culture polystyrene standard.

The effects of caffeic, coumaric and ferulic acids on proliferation, superoxide production, adhesion and migration of human tumor cells in vitro.

PubMed

Nasr Bouzaiene, Nouha; Kilani Jaziri, Soumaya; Kovacic, Hervé; Chekir-Ghedira, Leila; Ghedira, Kamel; Luis, José

2015-11-05

Reactive oxygen species are well-known mediators of various biological responses. In this study, we examined the effect of three phenolic acids, caffeic, coumaric and ferulic acids, on superoxide anion production, adhesion and migration of human lung (A549) and colon adenocarcinoma (HT29-D4) cancer cell lines. Proliferation of both tumor cells was inhibited by phenolic acids. Caffeic, coumaric and ferulic acids also significantly inhibited superoxide production in A549 and HT29-D4 cells. Superoxide anion production decreased by 92% and 77% at the highest tested concentration (200 µM) of caffeic acid in A549 and HT29-D4 cell lines respectively. Furthermore, A549 and HT29-D4 cell adhesion was reduced by 77.9% and 79.8% respectively at the higher tested concentration of ferulic acid (200 µM). Migration assay performed towards A549 cell line, revealed that tested compounds reduced significantly cell migration. At the highest concentration tested (200 µM), the covered surface was 7.7%, 9.5% and 35% for caffeic, coumaric or ferulic acids, respectively. These results demonstrate that caffeic, coumaric and ferulic acids may participate as active ingredients in anticancer agents against lung and colon cancer development, at adhesion and migration steps of tumor progression. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of Water-Glass Coating on HA and HA-TCP Samples for MSCs Adhesion, Proliferation, and Differentiation.

PubMed

Bajpai, Indu; Kim, Duk Yeon; Kyong-Jin, Jung; Song, In-Hwan; Kim, Sukyoung

2016-01-01

Ca-P and silicon based materials have become very popular as bone tissue engineering materials. In this study, water-glass (also known as sodium silicate glass) was coated on sintered hydroxyapatite (HA) and HA-TCP (TCP stands for tricalcium phosphate) samples and subsequently heat-treated at 600°C for 2 hrs. X-rays diffraction showed the presence of β- and α-TCP phases along with HA in the HA-TCP samples. Samples without coating, with water-glass coating, and heat-treated after water-glass coating were used to observe the adhesion and proliferation response of bone marrow derived-mesenchymal stem cells (MSCs). Cell culture was carried out for 4 hrs, 1 day, and 7 days. Interestingly, all samples showed similar response for cell adhesion and proliferation up to 7-day culture but fibronectin, E-cadherin, and osteogenic differentiation related genes (osteocalcin and osteopontin) were significantly induced in heat-treated water-glass coated HA-TCP samples. A water-glass coating on Ca-P samples was not found to influence the cell proliferation response significantly but activated some extracellular matrix genes and induced osteogenic differentiation in the MSCs.

The effects of focal adhesion kinase on the motility, proliferation and apoptosis of Caco2 and SMMC-7721 cells.

PubMed

Gao, Ning; He, Huimin; Xiao, Li; Gao, Xiaojie; Shi, Hongyan; Wu, Qiong; Xu, Nan; Lei, Yuqing; Song, Xigui; Hou, Yingchun

2015-04-01

Focal adhesion kinase (FAK) plays important roles in cancer development. However, the significance of FAK expression in colorectal carcinoma and hepatocellular carcinoma has not been clarified. This study aims to explore the roles FAK played in the progression of colorectal carcinoma and hepatocellular carcinoma. RNAi method was used to inhibit the expression of FAK in Caco2 and SMMC-7721 cells. Reverse transcriptase polymerase chain reaction analysis and Western blot analysis were used to examine mRNA and protein expression of FAK. Then, the proliferation, motility and apoptosis of both types of cells were detected using MTT assay, wound healing/transwell assay and nuclear staining assay. The microstructure changes (F-actin, β-tubulin and lamin B1) of SMMC-7721 cells were visualized by immunofluorescence. FAK was overexpressed in both cell lines and down-regulation of FAK resulted in suppression of cell proliferation, inhibition of cell migration and invasion. The apoptosis of cells was increased significantly following the FAK expression inhibition. Moreover, actin polymerization, β-tubulin and lamin B1 expression of cells were significantly decreased. The results highlight the role of FAK in the progression of cancers. These findings suggest FAK serve as a potential therapeutic target for cancer therapy.

Optimizing surface characteristics for cell adhesion and proliferation on titanium plasma spray coatings on polyetheretherketone.

PubMed

Yoon, Byung Jo Victor; Xavier, Fred; Walker, Brendon R; Grinberg, Samuel; Cammisa, Frank P; Abjornson, Celeste

2016-10-01

, NY, USA) using a backscattered detector. Image analysis of the CPTi coatings showed uniform and rough surfaces. For Phase 1, roughness was evaluated as fine, medium, and coarse. The eSEM image analysis and cell counting by DAPI demonstrated that hMSCs have a tendency to form stronger adhesion and greater pseudopodia extensions on fine roughness surfaces. Individual hMSCs were seen forming cytoplasmic processes extending across the width of a pore. There was a 4- and 20-fold reduction in adhered hMSCs with an increase to medium and coarse roughnesses, respectively. For Phase 2, studied groups are (1) medium CPTi coating with zirconia polishing, (2) medium CPTi coating with CPTi polishing, and (3) fine CPTi coating with CPTi polishing. The eSEM image analysis and cell counting by DAPI demonstrated that hMSCs have a tendency to form stronger adhesion and greater pseudopodia extensions on Group 3 over the other two groups. There was a twofold reduction in adhered hMSCs on medium roughness relative to fine. No difference in cell adhesion was found between Groups 1 and 2. Individual hMSCs were seen forming cytoplasmic processes extending across the width of a pore. Previously, it was accepted without much scrutiny that surface coatings were beneficial. This study begins to discover that surface topography directly affects the potential for cells to adhere and proliferate and lead to greater surgical efficacy. Copyright © 2016 Elsevier Inc. All rights reserved.

Hydroxyapatite promotes superior keratocyte adhesion and proliferation in comparison with current keratoprosthesis skirt materials.

PubMed

Mehta, J S; Futter, C E; Sandeman, S R; Faragher, R G A F; Hing, K A; Tanner, K E; Allan, B D S

2005-10-01

Published clinical series suggest the osteoodontokeratoprosthesis (OOKP) may have a lower extrusion rate than current synthetic keratoprostheses. The OOKP is anchored in the eye wall by autologous tooth. The authors' aim was to compare adhesion, proliferation, and morphology for telomerase transformed keratocytes seeded on calcium hydroxyapatite (the principal mineral constituent of tooth) and materials used in the anchoring elements of commercially available synthetic keratoprostheses. Test materials were hydroxyapatite, polytetrafluoroethylene (PTFE), polyhydroxyethyl methacrylate (HEMA), and glass (control). Cell adhesion and viability were quantified at 4 hours, 24 hours, and 1 week using a calcein-AM/EthD-1 viability/cytotoxicity assay. Focal contact expression and cytoskeletal organisation were studied at 24 hours by confocal microscopy with immunoflourescent labelling. Further studies of cell morphology were performed using light and scanning electron microscopy. Live cell counts were significantly greater on hydroxyapatite surfaces at each time point (p<0.04). Dead cell counts were significantly higher for PTFE at 7 days (p<0.002). ss(1) integrin expression was highest on hydroxyapatite. Adhesion structures were well expressed in flat, spread out keratocytes on both HA and glass. Keratocytes tended to be thinner and spindle shaped on PTFE. The relatively few keratocytes visible on HEMA test surfaces were rounded and poorly adherent. Keratocyte adhesion, spreading, and viability on hydroxyapatite test surfaces is superior to that seen on PTFE and HEMA. Improving the initial cell adhesion environment in the skirt element of keratoprostheses may enhance tissue integration and reduce device failure rates.

ROCK Inhibitor Enhances Adhesion and Wound Healing of Human Corneal Endothelial Cells

PubMed Central

Pipparelli, Aurélien; Arsenijevic, Yvan; Thuret, Gilles; Gain, Philippe

2013-01-01

Maintenance of corneal transparency is crucial for vision and depends mainly on the endothelium, a non-proliferative monolayer of cells covering the inner part of the cornea. When endothelial cell density falls below a critical threshold, the barrier and “pump” functions of the endothelium are compromised which results in corneal oedema and loss of visual acuity. The conventional treatment for such severe disorder is corneal graft. Unfortunately, there is a worldwide shortage of donor corneas, necessitating amelioration of tissue survival and storage after harvesting. Recently it was reported that the ROCK inhibitor Y-27632 promotes adhesion, inhibits apoptosis, increases the number of proliferating monkey corneal endothelial cells in vitro and enhance corneal endothelial wound healing both in vitro and in vivo in animal models. Using organ culture human cornea (N = 34), the effect of ROCK inhibitor was evaluated in vitro and ex vivo. Toxicity, corneal endothelial cell density, cell proliferation, apoptosis, cell morphometry, adhesion and wound healing process were evaluated by live/dead assay standard cell counting method, EdU labelling, Ki67, Caspase3, Zo-1 and Actin immunostaining. We demonstrated for the first time in human corneal endothelial cells ex vivo and in vitro, that ROCK inhibitor did not induce any toxicity effect and did not alter cell viability. ROCK inhibitor treatment did not induce human corneal endothelial cells proliferation. However, ROCK inhibitor significantly enhanced adhesion and wound healing. The present study shows that the selective ROCK inhibitor Y-27632 has no effect on human corneal endothelial cells proliferative capacities, but alters cellular behaviours. It induces changes in cell shape, increases cell adhesion and enhances wound healing ex vivo and in vitro. Its absence of toxicity, as demonstrated herein, is relevant for its use in human therapy. PMID:23626771

Low-expression of E-cadherin in leukaemia cells causes loss of homophilic adhesion and promotes cell growth.

PubMed

Rao, Qing; Wang, Ji-Ying; Meng, Jihong; Tang, Kejing; Wang, Yanzhong; Wang, Min; Xing, Haiyan; Tian, Zheng; Wang, Jianxiang

2011-09-01

E-cadherin (epithelial cadherin) belongs to the calcium-dependent adhesion molecule superfamily and is implicated in the interactions of haematopoietic progenitors and bone marrow stromal cells. Adhesion capacity to bone marrow stroma was impaired for leukaemia cells, suggesting that a breakdown of adhesive mechanisms governed by an adhesion molecule may exist in leukaemic microenvironment. We previously found that E-cadherin was low expressed in primary acute leukaemia cells compared with normal bone marrow mononuclear cells. In this study, we investigate the functional importance of low E-cadherin expression in leukaemia cell behaviours and investigate its effects in the abnormal interaction of leukaemic cells with stromal cells. After expression of E-cadherin was restored by a demethylating agent in leukaemia cells, E-cadherin-specific adhesion was enhanced. Additionally, siRNA (small interfering RNA)-mediated silencing of E-cadherin in Raji cells resulted in a reduction of cell homophilic adhesion and enhancement of cell proliferation and colony formation. These results suggest that low expression of E-cadherin contributes to the vigorous growth and transforming ability of leukaemic cells.

Cell Attachment and Proliferation of Human Adipose-Derived Stem Cells on PLGA/Chitosan Electrospun Nano-Biocomposite.

PubMed

Razavi, Shahnaz; Karbasi, Saeed; Morshed, Mohammad; Zarkesh Esfahani, Hamid; Golozar, Mohammad; Vaezifar, Sedigheh

2015-01-01

In this study, nano-biocomposite composed of poly (lactide-co-glycolide) (PLGA) and chitosan (CS) were electrospun through a single nozzle by dispersing the CS nano-powders in PLGA solution. The cellular behavior of human adipose derived stem cells (h-ADSCs) on random and aligned scaffolds was then evaluated. In this experimental study, the PLGA/CS scaffolds were prepared at the different ratios of 90/10, 80/20, and 70/30 (w/w) %. Morphology, cell adhesion and prolif- eration rate of h-ADSCs on the scaffolds were assessed using scanning electron microscope (SEM), 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay and trypan blue staining respectively. H-ADSCs seeded on the matrices indicated that the PLGA/CS composite matrix with aligned nanofibres and higher content of CS nano-powders gave significantly better performance than others in terms of cell adhesion and proliferation rate (P<0.05). We found that CS enhanced cell adhesion and proliferation rate, and aligned nanofibers guided cell growth along the longitudinal axis of the nanofibers, which would provide a beneficial approach for tissue engineering.

Lensless imaging system to quantify cell proliferation

NASA Astrophysics Data System (ADS)

Vinjimore Kesavan, S.; Allier, C. P.; Navarro, F.; Mittler, F.; Chalmond, B.; Dinten, J.-M.

2013-02-01

Owing to its simplicity, lensless imaging system is adept at continuous monitoring of adherent cells inside the incubator. The setup consists of a CMOS sensor with pixel pitch of 2.2 μm and field of view of 24 mm2, LED with a dominating wavelength of 525 nm, along with a pinhole of 150 μm as the source of illumination. The in-line hologram obtained from cells depends on the degree of cell-substrate adhesion. Drastic difference is observed between the holographic patterns of floating and adherent cells. In addition, the well-established fact of reduction of cell-substrate contact during cell division is observed with our system based on corresponding spontaneous transition in the holographic pattern. Here, we demonstrate that by recognizing this specific holographic pattern, number of cells undergoing mitosis in a cell culture with a population of approximately 5000 cells, can be estimated in real-time. The method is assessed on comparison with Edu-based proliferation assay. The approach is straightforward and it eliminates the use of markers to estimate the proliferation rate of a given cell culture. Unlike most proliferation assays, the cells are not harvested enabling continuous monitoring of cell culture.

Tuning cell adhesive properties via layer-by-layer assembly of chitosan and alginate

PubMed Central

Silva, Joana M.; García, José R.; Reis, Rui L.; García, Andrés J.; Mano, João F.

2017-01-01

Understanding the mechanisms controlling cell-multilayer film interactions is crucial to the successful engineering of these coatings for biotechnological and biomedical applications. Herein, we present a strategy to tune the cell adhesive properties of multilayers based on marine polysaccharides with and without cross-linking and/or coating with extracellular matrix proteins. Chemical cross-linking of multilayers improved mechanical properties of the coatings but also elicited changes in surface chemistry that alter the adhesion of human umbilical vein endothelial cells. We evaluated a strategy to decouple the mechanical and chemical properties of these films, enabling the transition from cell-adhesive to cell-resistant multilayers. Addition of chitosan/alginate multilayers on top of cross-linked films decreased endothelial cell adhesion, spreading, and proliferation to similar levels as uncross-linked films. Our findings highlight the key role of surface chemistry in cell-multilayer film interactions, and these engineered nanocoatings represent a tunable model of cell adhesive and non-adhesive multilayered films. PMID:28126597

Intercellular adhesion molecule-1 expression by skeletal muscle cells augments myogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goh, Qingnian; Dearth, Christopher L.; Corbett, Jacob T.

We previously demonstrated that the expression of intercellular adhesion molecule-1 (ICAM-1) by skeletal muscle cells after muscle overload contributes to ensuing regenerative and hypertrophic processes in skeletal muscle. The objective of the present study is to reveal mechanisms through which skeletal muscle cell expression of ICAM-1 augments regenerative and hypertrophic processes of myogenesis. This was accomplished by genetically engineering C2C12 myoblasts to stably express ICAM-1, and by inhibiting the adhesive and signaling functions of ICAM-1 through the use of a neutralizing antibody or cell penetrating peptide, respectively. Expression of ICAM-1 by cultured skeletal muscle cells augmented myoblast–myoblast adhesion, myotube formation,more » myonuclear number, myotube alignment, myotube–myotube fusion, and myotube size without influencing the ability of myoblasts to proliferate or differentiate. ICAM-1 augmented myotube formation, myonuclear accretion, and myotube alignment through a mechanism involving adhesion-induced activation of ICAM-1 signaling, as these dependent measures were reduced via antibody and peptide inhibition of ICAM-1. The adhesive and signaling functions of ICAM-1 also facilitated myotube hypertrophy through a mechanism involving myotube–myotube fusion, protein synthesis, and Akt/p70s6k signaling. Our findings demonstrate that ICAM-1 expression by skeletal muscle cells augments myogenesis, and establish a novel mechanism through which the inflammatory response facilitates growth processes in skeletal muscle. - Highlights: • We examined mechanisms through which skeletal muscle cell expression of ICAM-1 facilitates events of in vitro myogenesis. • Expression of ICAM-1 by cultured myoblasts did not influence their ability to proliferate or differentiate. • Skeletal muscle cell expression of ICAM-1 augmented myoblast fusion, myotube alignment, myotube–myotube fusion, and myotube size. • ICAM-1 augmented myogenic processes

Adhesion-mediated self-renewal abilities of Ph+ blastoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Funayama, Keiji; Saito-Kurimoto, Yumi; Ebihara, Yasuhiro

2010-05-28

The Philadelphia chromosome-positive blastoma, maintained by serial subcutaneous transplantation in nude mice, is a highly proliferating biological mass consisting of homogenous CD34{sup +}CD38{sup -} myeloblastoid cells. These cells newly evolved from pluripotent leukemia stem cells of chronic myeloid leukemia in the chronic phase. Therefore, this mass may provide a unique tool for better understanding cellular and molecular mechanisms of self-renewal of leukemia stem cells. In this paper, we demonstrated that intravenously injected blastoma cells can cause Ph+ blastic leukemia with multiple invasive foci in NOD/SCID mice but not in nude mice. In addition, using an in vitro culture system, wemore » clearly showed that blastoma cell adhesion to OP9 stromal cells accelerates blastoma cell proliferation that is associated with up-regulation of BMI1 gene expression; increased levels of {beta}-catenin and the Notch1 intra-cellular domain; and changed the expression pattern of variant CD44 forms, which are constitutively expressed in these blastoma cells. These findings strongly suggest that adhesion of leukemic stem cells to stromal cells via CD44 might be indispensable for their cellular defense against attack by immune cells and for maintenance of their self-renewal ability.« less

Redundant control of migration and adhesion by ERM proteins in vascular smooth muscle cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baeyens, Nicolas; Latrache, Iman; Yerna, Xavier

Highlights: •The three ERM proteins are expressed in vascular smooth muscle cell. •ERM depletion inhibited PDGF-evoked migration redundantly. •ERM depletion increased cell adhesion redundantly. •ERM depletion did not affect PDGF-evoked Ca signal, Rac1 activation, proliferation. •ERM proteins control PDGF-induced migration by regulating adhesion. -- Abstract: Ezrin, radixin, and moesin possess a very similar structure with a C-terminal actin-binding domain and a N-terminal FERM interacting domain. They are known to be involved in cytoskeleton organization in several cell types but their function in vascular smooth muscle cells (VSMC) is still unknown. The aim of this study was to investigate the rolemore » of ERM proteins in cell migration induced by PDGF, a growth factor involved in pathophysiological processes like angiogenesis or atherosclerosis. We used primary cultured VSMC obtained from rat aorta, which express the three ERM proteins. Simultaneous depletion of the three ERM proteins with specific siRNAs abolished the effects of PDGF on cell architecture and migration and markedly increased cell adhesion and focal adhesion size, while these parameters were only slightly affected by depletion of ezrin, radixin or moesin alone. Rac1 activation, cell proliferation, and Ca{sup 2+} signal in response to PDGF were unaffected by ERM depletion. These results indicate that ERM proteins exert a redundant control on PDGF-induced VSMC migration by regulating focal adhesion turn-over and cell adhesion to substrate.« less

Single and collective cell migration: the mechanics of adhesions

PubMed Central

De Pascalis, Chiara; Etienne-Manneville, Sandrine

2017-01-01

Chemical and physical properties of the environment control cell proliferation, differentiation, or apoptosis in the long term. However, to be able to move and migrate through a complex three-dimensional environment, cells must quickly adapt in the short term to the physical properties of their surroundings. Interactions with the extracellular matrix (ECM) occur through focal adhesions or hemidesmosomes via the engagement of integrins with fibrillar ECM proteins. Cells also interact with their neighbors, and this involves various types of intercellular adhesive structures such as tight junctions, cadherin-based adherens junctions, and desmosomes. Mechanobiology studies have shown that cell–ECM and cell–cell adhesions participate in mechanosensing to transduce mechanical cues into biochemical signals and conversely are responsible for the transmission of intracellular forces to the extracellular environment. As they migrate, cells use these adhesive structures to probe their surroundings, adapt their mechanical properties, and exert the appropriate forces required for their movements. The focus of this review is to give an overview of recent developments showing the bidirectional relationship between the physical properties of the environment and the cell mechanical responses during single and collective cell migration. PMID:28684609

Matrix stiffness reverses the effect of actomyosin tension on cell proliferation.

PubMed

Mih, Justin D; Marinkovic, Aleksandar; Liu, Fei; Sharif, Asma S; Tschumperlin, Daniel J

2012-12-15

The stiffness of the extracellular matrix exerts powerful effects on cell proliferation and differentiation, but the mechanisms transducing matrix stiffness into cellular fate decisions remain poorly understood. Two widely reported responses to matrix stiffening are increases in actomyosin contractility and cell proliferation. To delineate their relationship, we modulated cytoskeletal tension in cells grown across a physiological range of matrix stiffnesses. On both synthetic and naturally derived soft matrices, and across a panel of cell types, we observed a striking reversal of the effect of inhibiting actomyosin contractility, switching from the attenuation of proliferation on rigid substrates to the robust promotion of proliferation on soft matrices. Inhibiting contractility on soft matrices decoupled proliferation from cytoskeletal tension and focal adhesion organization, but not from cell spread area. Our results demonstrate that matrix stiffness and actomyosin contractility converge on cell spreading in an unexpected fashion to control a key aspect of cell fate.

Microfluidic devices for cell cultivation and proliferation

PubMed Central

Tehranirokh, Masoomeh; Kouzani, Abbas Z.; Francis, Paul S.; Kanwar, Jagat R.

2013-01-01

Microfluidic technology provides precise, controlled-environment, cost-effective, compact, integrated, and high-throughput microsystems that are promising substitutes for conventional biological laboratory methods. In recent years, microfluidic cell culture devices have been used for applications such as tissue engineering, diagnostics, drug screening, immunology, cancer studies, stem cell proliferation and differentiation, and neurite guidance. Microfluidic technology allows dynamic cell culture in microperfusion systems to deliver continuous nutrient supplies for long term cell culture. It offers many opportunities to mimic the cell-cell and cell-extracellular matrix interactions of tissues by creating gradient concentrations of biochemical signals such as growth factors, chemokines, and hormones. Other applications of cell cultivation in microfluidic systems include high resolution cell patterning on a modified substrate with adhesive patterns and the reconstruction of complicated tissue architectures. In this review, recent advances in microfluidic platforms for cell culturing and proliferation, for both simple monolayer (2D) cell seeding processes and 3D configurations as accurate models of in vivo conditions, are examined. PMID:24273628

Photoinitiator-Free Synthesis of Endothelial Cell Adhesive and Enzymatically Degradable Hydrogels

PubMed Central

Jones, Derek R.; Marchant, Roger E.; von Recum, Horst; Gupta, Anirban Sen; Kottke-Marchant, Kandice

2015-01-01

We report on a photoinitiator-free synthetic method of incorporating bioactivity into poly(ethylene glycol) (PEG) hydrogels in order to control physical properties, enzymatic biodegradability and cell-specific adhesiveness of the polymer network, while eliminating the need for UV-mediated photopolymerization. To accomplish this, hydrogel networks were polymerized using Michael addition with four-arm PEG acrylate (10 kDa), using a collagenase sensitive peptide (CSP) as a crosslinker, and introducing an endothelial cell adhesive peptide either terminally (RGD) or attached to the crosslinking peptide sequence (CSP-RGD). The efficiency of the Michael addition reactions were determined by NMR and Ellman’s assay. Successful decoupling of cell adhesivity and physical properties was demonstrated by quantifying and comparing the swelling ratios and Young’s Moduli of various hydrogel formulations. Degradation profiles were established by incubating functionalized hydrogels in collagenase solutions (0.0 – 1.0 µg/mL), demonstrating that functionalized hydrogels degraded at a rate dependent upon collagenase concentration. Moreover, it was shown that the degradation rate was independent of CSP-RGD concentration. Cell attachment and proliferation on functionalized hydrogels were compared for various RGD concentrations, providing evidence that cell attachment and proliferation were directly related to relative amounts of the CSP-RGD combination peptide. An increase in cell viability was achieved using Michael addition techniques when compared to UV-polymerization, and was assessed by a LIVE/DEAD fluorescence assay. This photoinitiator-free method shows promise in creating hydrogel-based tissue engineering scaffolds allow for decoupled cell adhesivity and physical properties and that render greater cell viability. PMID:25462848

Matrix stiffness reverses the effect of actomyosin tension on cell proliferation

PubMed Central

Mih, Justin D.; Marinkovic, Aleksandar; Liu, Fei; Sharif, Asma S.; Tschumperlin, Daniel J.

2012-01-01

Summary The stiffness of the extracellular matrix exerts powerful effects on cell proliferation and differentiation, but the mechanisms transducing matrix stiffness into cellular fate decisions remain poorly understood. Two widely reported responses to matrix stiffening are increases in actomyosin contractility and cell proliferation. To delineate their relationship, we modulated cytoskeletal tension in cells grown across a physiological range of matrix stiffnesses. On both synthetic and naturally derived soft matrices, and across a panel of cell types, we observed a striking reversal of the effect of inhibiting actomyosin contractility, switching from the attenuation of proliferation on rigid substrates to the robust promotion of proliferation on soft matrices. Inhibiting contractility on soft matrices decoupled proliferation from cytoskeletal tension and focal adhesion organization, but not from cell spread area. Our results demonstrate that matrix stiffness and actomyosin contractility converge on cell spreading in an unexpected fashion to control a key aspect of cell fate. PMID:23097048

Cell Attachment and Proliferation of Human Adipose-Derived Stem Cells on PLGA/Chitosan Electrospun Nano-Biocomposite

PubMed Central

Razavi, Shahnaz; Karbasi, Saeed; Morshed, Mohammad; Zarkesh Esfahani, Hamid; Golozar, Mohammad; Vaezifar, Sedigheh

2015-01-01

Objective In this study, nano-biocomposite composed of poly (lactide-co-glycolide) (PLGA) and chitosan (CS) were electrospun through a single nozzle by dispersing the CS nano-powders in PLGA solution. The cellular behavior of human adipose derived stem cells (h-ADSCs) on random and aligned scaffolds was then evaluated. Materials and Methods In this experimental study, the PLGA/CS scaffolds were prepared at the different ratios of 90/10, 80/20, and 70/30 (w/w) %. Morphology, cell adhesion and prolif- eration rate of h-ADSCs on the scaffolds were assessed using scanning electron microscope (SEM), 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay and trypan blue staining respectively. Results H-ADSCs seeded on the matrices indicated that the PLGA/CS composite matrix with aligned nanofibres and higher content of CS nano-powders gave significantly better performance than others in terms of cell adhesion and proliferation rate (P<0.05). Conclusion We found that CS enhanced cell adhesion and proliferation rate, and aligned nanofibers guided cell growth along the longitudinal axis of the nanofibers, which would provide a beneficial approach for tissue engineering. PMID:26464814

Upregulation of nuclear transporter, Kpnβ1, contributes to accelerated cell proliferation- and cell adhesion-mediated drug resistance (CAM-DR) in diffuse large B-cell lymphoma.

PubMed

He, Song; Miao, Xiaobing; Wu, Yaxun; Zhu, Xinghua; Miao, Xianjing; Yin, Haibing; He, Yunhua; Li, Chunsun; Liu, Yushan; Lu, Xiaoyun; Chen, Yali; Wang, Yuchan; Xu, Xiaohong

2016-03-01

The Karyopherin proteins are involved in the shuttling of cargo proteins, and certain RNAs, across the nuclear pore complex into and out of the cell nucleus. Karyopherin β1 (Kpnβ1) is a member of the Karyopherin β superfamily of nuclear transport proteins. In addition to the nuclear import function, Kpnβ1 is associated with the occurrence of tumors. This study investigated the expression and biologic function of Kpnβ1 in diffuse large B-cell lymphoma (DLBCL). The prognostic value of Kpnβ1 expression was evaluated using immunohistochemical staining. The role of Kpnβ1 on cell proliferation- and cell adhesion-mediated drug resistance (CAM-DR) was also determined. We demonstrated that Kpnβ1 mRNA and protein expression levels were significantly higher in DLBCL B-cells and DLBCL cell lines than in normal CD19 purified B-cells. Immunohistochemical analysis suggested that the expression of Kpnβ1 was correlated with Ki-67 (P < 0.001). Kaplan-Meier curve showed that high expression of Kpnβ1 was significantly associated with shorter overall survival. In addition, Kpnβ1 was associated with the proliferation of DLBCL cells. Importantly, we found that Kpnβ1 could interact with p65 and promote CAM-DR via accelerating NF-κB activation in DLBCL. Patients with tumors highly expressing Kpnβ1 have poorer overall survivals. Kpnβ1 interacts with p65 and enhances CAM-DR.

Effect of PDGF-BB combined with EDTA gel on adhesion and proliferation to the root surface.

PubMed

Belal, Mahmoud Helmy; Watanabe, Hisashi; Ichinose, Shizuko; Ishikawa, Isao

2012-07-01

Periodontal regeneration using EDTA or PDGF showed promising results, but the effect of combined application was still unclear. This study aimed to verify the effect of EDTA and/or PDGF application on root adhesion and proliferation of PDL fibroblast cells. Eighty specimens were prepared from forty periodontitis teeth and made five groups: (1) diseased (untreated), (2) SRP (scaling root planing), (3) EDTA (24%), (4) PDGF (25 ng/ml) and (5) Combined application of EDTA and PDGF. Periodontal ligament cells were cultured on the above conditioned dentin plate, and SEM examination was preformed and cells were counted within a representative standard area for both cell morphology and density. All groups including untreated showed significantly increase of adhered cells from baseline to 7 days. Among them, rate of increase was much higher in EDTA, PDGF, and combined groups. ANOVA test indicated that the number of cells in PDGF and combined groups was significantly higher than diseased group at 1 day. On day 7, PDGF and combined groups showed significantly higher number of adhesion cells than that found in the diseased, SRP and EDTA groups. Thus, root conditioning with EDTA enhanced cell adhesion more than SRP alone. There was no significant difference of cell number between PDGF and combined group. Combined application of EDTA and PDGF increased significantly PDL cell adhesion than EDTA alone. PDGF alone, however, also showed comparable effect to combined application at all periods. Thus, synergistic effect between PDGF and EDTA was not observed.

Anti-sense suppression of epidermal growth factor receptor expression alters cellular proliferation, cell-adhesion and tumorigenicity in ovarian cancer cells.

PubMed

Alper, O; De Santis, M L; Stromberg, K; Hacker, N F; Cho-Chung, Y S; Salomon, D S

2000-11-15

Over-expression of epidermal growth factor receptor (EGFR) in ovarian cancer has been well documented. Human NIH:OVCAR-8 ovarian carcinoma cells were transfected with an expression vector containing the anti-sense orientation of truncated human EGFR cDNA. EGFR anti-sense over-expression resulted in decreased EGFR protein and mRNA expression, cell proliferation and tumor formation in nude mice. In accordance with the reduced levels of EGFR in EGFR anti-sense-expressing cells, tyrosine phosphorylation of EGFR was decreased compared to untransfected parental cells treated with EGF. In EGFR anti-sense-transfected cells, expression of erbB-3, but not erbB-2, was increased. In addition, basal and heregulin-beta 1-stimulated tyrosine phosphorylation of erbB-3 was higher in EGFR anti-sense vector-transfected cells. A morphological alteration in EGFR anti-sense gene-expressing cells was correlated with a decrease in the expression of E-cadherin, alpha-catenin and, to a lesser extent, beta-catenin. Changes in the expression of these proteins were associated with a reduction in complex formation among E-cadherin, beta-catenin and alpha-catenin and between beta-catenin and EGFR in EGFR anti-sense-expressing cells compared to sense-transfected control cells. These results demonstrate that EGFR expression in ovarian carcinoma cells regulates expression of cell adhesion proteins that may enhance cell growth and invasiveness. Copyright 2000 Wiley-Liss, Inc.

[The effect of Angelica sinensis on adhesion, invasion, migration and metastasis of melanoma cells].

PubMed

Gu, Qin; Xu, Jian-ya; Cheng, Luo-gen; Xia, Wei-jun

2007-03-01

To study the effect of Angelica sinensis on invasion, adhesion, migration and metastasis of B16-BL6 metastatic mouse melanoma cells and discuss its functional mechanism. The proliferation, adhesion, invasion and migration capacity of B16-BL6 metastatic cells was evaluated by MTT assay, adhesion assay and reconstituted basement membrane invasion and migration assay in vitro respectively. Mouse spontaneous melanoma model was used to study the effect of Angelica sinensis on metastasis in vivo. The extract of Angelica sinensis inhibited the proliferation of B16-BL6 metastatic cells and its migration capacity significantly. It regulated bidirectionally the adhesion of B16-BL6 metastatic cells to the basement component laminin while it had no effect on the invasion capacity. In the mouse spotaneous melanoma model, the lung metastatic nodes number and its volume were significantly decreased after continuously treated with the extract of Angelica sinensis at the concentration of 3.67 mg/kg. The extract of Angelica sinensis can inhibit the metastasis of of B16-BL6 metastatic mouse melanoma cells and its mechanism is maybe that Angelica sinensis can inhibit the B16-BL6 cells adhering to the ECM and reduce the migration of B16-BL6 cells.

Multiscale Morphology of Organic Semiconductor Thin Films Controls the Adhesion and Viability of Human Neural Cells

PubMed Central

Tonazzini, I.; Bystrenova, E.; Chelli, B.; Greco, P.; Stoliar, P.; Calò, A.; Lazar, A.; Borgatti, F.; D'Angelo, P.; Martini, C.; Biscarini, F.

2010-01-01

Abstract We investigate how multiscale morphology of functional thin films affects the in vitro behavior of human neural astrocytoma 1321N1 cells. Pentacene thin film morphology is precisely controlled by means of the film thickness, Θ (here expressed in monolayers (ML)). Fluorescence and atomic force microscopy allow us to correlate the shape, adhesion, and proliferation of cells to the morphological properties of pentacene films controlled by saturated roughness, σ, correlation length, ξ, and fractal dimension, df. At early incubation times, cell adhesion exhibits a transition from higher to lower values at Θ ≈ 10 ML. This is explained using a model of conformal adhesion of the cell membrane onto the growing pentacene islands. From the model fitting of the data, we show that the cell explores the surface with a deformation of the membrane whose minimum curvature radius is 90 (± 45) nm. The transition in the adhesion at ∼10 ML arises from the saturation of ξ accompanied by the monotonic increase of σ, which leads to a progressive decrease of the pentacene local radius of curvature and hence to the surface area accessible to the cell. Cell proliferation is also enhanced for Θ < 10 ML, and the optimum morphology parameter ranges for cell deployment and growth are σ ≤ 6 nm, ξ > 500 nm, and df > 2.45. The characteristic time of cell proliferation is τ ≈ 10 ± 2 h. PMID:20550892

Influence on proliferation and adhesion of human gingival fibroblasts from different titanium surface decontamination treatments: An in vitro study.

PubMed

Cao, Jie; Wang, Tong; Pu, Yinfei; Tang, Zhihui; Meng, Huanxin

2018-03-01

To investigate the effects of different decontamination treatments on microstructure of titanium (Ti) surface as well as proliferation and adhesion of human gingival fibroblasts (HGFs). Ti discs with machined (M) and sand blasted, acid etched (SAE) surfaces were treated with five different decontamination treatments: (1) stainless steel curette (SSC), ultrasonic system with (2) straight carbon fiber tip (UCF) or (3) metal tip (UM), (4) rotating Ti brush (RTB), and (5) Er:YAG laser (30 mJ/pulse at 30 Hz). Surface roughness was analyzed under optical interferometry. HGFs were cultured on each disc. Proliferation and adhesive strength were analyzed. qRT-PCR and ELISA were performed to detect the RNA and protein expression of FAK, ITGB1, COL1A1, and FN1 respectively from different Ti surfaces. Surface roughness increased on M surface. Proliferation, adhesive strength and gene expression were higher on M surface than SAE surface. Decontamination treatments affected surface parameters significantly (P < 0.001), making M surface less smooth while SAE surface became less rough. SSC, UCF, UM and RTB decreased proliferation on M surfaces significantly (P < 0.05). UCF, RTB and laser increased proliferation on SAE surface significantly (P < 0.05). UM decreased adhesive strength on M surface significantly and laser increased adhesive strength on SAE surface significantly (P < 0.05). Gene expression increased with time and was altered by decontamination treatments significantly (P < 0.001). Decontamination treatments influence surface roughness and cell behavior of HGFs. Laser might be an optimal decontamination treatment which has the least negative effect on M surface and the most positive effect on SAE surface. Copyright © 2017 Elsevier Ltd. All rights reserved.

Silicon-hydroxyapatite bioactive coatings (Si-HA) from diatomaceous earth and silica. Study of adhesion and proliferation of osteoblast-like cells.

PubMed

López-Alvarez, M; Solla, E L; González, P; Serra, J; León, B; Marques, A P; Reis, R L

2009-05-01

The aim of this study consisted on investigating the influence of silicon substituted hydroxyapatite (Si-HA) coatings over the human osteoblast-like cell line (SaOS-2) behaviour. Diatomaceous earth and silica, together with commercial hydroxyapatite were respectively the silicon and HA sources used to produce the Si-HA coatings. HA coatings with 0 wt% of silicon were used as control of the experiment. Pulsed laser deposition (PLD) was the selected technique to deposit the coatings. The Si-HA thin films were characterized by Fourier Transformed Infrared Spectroscopy (FTIR) demonstrating the efficient transfer of Si to the HA structure. The in vitro cell culture was established to assess the cell attachment, proliferation and osteoblastic activity respectively by, Scanning Electron Microscopy (SEM), DNA and alkaline phosphatase (ALP) quantification. The SEM analysis demonstrated a similar adhesion behaviour of the cells on the tested materials and the maintenance of the typical osteoblastic morphology along the time of culture. The Si-HA coatings did not evidence any type of cytotoxic behaviour when compared with HA coatings. Moreover, both the proliferation rate and osteoblastic activity results showed a slightly better performance on the Si-HA coatings from diatoms than on the Si-HA from silica.

Viability and proliferation of endothelial cells upon exposure to GaN nanoparticles

PubMed Central

Braniste, Tudor; Tiginyanu, Ion; Horvath, Tibor; Raevschi, Simion; Cebotari, Serghei; Lux, Marco; Haverich, Axel

2016-01-01

Summary Nanotechnology is a rapidly growing and promising field of interest in medicine; however, nanoparticle–cell interactions are not yet fully understood. The goal of this work was to examine the interaction between endothelial cells and gallium nitride (GaN) semiconductor nanoparticles. Cellular viability, adhesion, proliferation, and uptake of nanoparticles by endothelial cells were investigated. The effect of free GaN nanoparticles versus the effect of growing endothelial cells on GaN functionalized surfaces was examined. To functionalize surfaces with GaN, GaN nanoparticles were synthesized on a sacrificial layer of zinc oxide (ZnO) nanoparticles using hydride vapor phase epitaxy. The uptake of GaN nanoparticles by porcine endothelial cells was strongly dependent upon whether they were fixed to the substrate surface or free floating in the medium. The endothelial cells grown on surfaces functionalized with GaN nanoparticles demonstrated excellent adhesion and proliferation, suggesting good biocompatibility of the nanostructured GaN. PMID:27826507

Viability and proliferation of endothelial cells upon exposure to GaN nanoparticles.

PubMed

Braniste, Tudor; Tiginyanu, Ion; Horvath, Tibor; Raevschi, Simion; Cebotari, Serghei; Lux, Marco; Haverich, Axel; Hilfiker, Andres

2016-01-01

Nanotechnology is a rapidly growing and promising field of interest in medicine; however, nanoparticle-cell interactions are not yet fully understood. The goal of this work was to examine the interaction between endothelial cells and gallium nitride (GaN) semiconductor nanoparticles. Cellular viability, adhesion, proliferation, and uptake of nanoparticles by endothelial cells were investigated. The effect of free GaN nanoparticles versus the effect of growing endothelial cells on GaN functionalized surfaces was examined. To functionalize surfaces with GaN, GaN nanoparticles were synthesized on a sacrificial layer of zinc oxide (ZnO) nanoparticles using hydride vapor phase epitaxy. The uptake of GaN nanoparticles by porcine endothelial cells was strongly dependent upon whether they were fixed to the substrate surface or free floating in the medium. The endothelial cells grown on surfaces functionalized with GaN nanoparticles demonstrated excellent adhesion and proliferation, suggesting good biocompatibility of the nanostructured GaN.

Adsorption of enamel matrix proteins to a bovine-derived bone grafting material and its regulation of cell adhesion, proliferation, and differentiation.

PubMed

Miron, Richard J; Bosshardt, Dieter D; Hedbom, Erik; Zhang, Yufeng; Haenni, Beat; Buser, Daniel; Sculean, Anton

2012-07-01

The use of various combinations of enamel matrix derivative (EMD) and grafting materials has been shown to promote periodontal wound healing/regeneration. However, the downstream cellular behavior of periodontal ligament (PDL) cells and osteoblasts has not yet been studied. Furthermore, it is unknown to what extent the bleeding during regenerative surgery may influence the adsorption of exogenous proteins to the surface of bone grafting materials and the subsequent cellular behavior. In the present study, the aim is to test EMD adsorption to the surface of natural bone mineral (NBM) particles in the presence of blood and determine the effect of EMD coating to NBM particles on downstream cellular pathways, such as adhesion, proliferation, and differentiation of primary human osteoblasts and PDL cells. NBM particles were precoated in various settings with EMD or human blood and analyzed for protein adsorption patterns via fluorescent imaging and high-resolution immunocytochemistry with an anti-EMD antibody. Cell attachment and cell proliferation were quantified using fluorescent double-stranded DNA-binding dye. Cell differentiation was analyzed using real-time polymerase chain reaction for genes encoding runt-related transcription factor 2, alkaline phosphatase (ALP), osteocalcin (OC), and collagen1α1 (COL1A1), and mineralization was assessed using red dye staining. Analysis of cell attachment and cell proliferation revealed significantly higher osteoblast and PDL cell attachment on EMD-coated surfaces when compared with control and blood-coated surfaces. EMD also stimulated release of growth factors and cytokines, including bone morphogenetic protein 2 and transforming growth factor β1. Moreover, there were significantly higher mRNA levels of osteoblast differentiation markers, including COL1A1, ALP, and OC, in osteoblasts and PDL cells cultured on EMD-coated NBM particles. The present results suggest that 1) EMD enhances osteoblast and PDL cell attachment

Non-viral gene delivery regulated by stiffness of cell adhesion substrates.

PubMed

Kong, Hyun Joon; Liu, Jodi; Riddle, Kathryn; Matsumoto, Takuya; Leach, Kent; Mooney, David J

2005-06-01

Non-viral gene vectors are commonly used for gene therapy owing to safety concerns with viral vectors. However, non-viral vectors are plagued by low levels of gene transfection and cellular expression. Current efforts to improve the efficiency of non-viral gene delivery are focused on manipulations of the delivery vector, whereas the influence of the cellular environment in DNA uptake is often ignored. The mechanical properties (for example, rigidity) of the substrate to which a cell adheres have been found to mediate many aspects of cell function including proliferation, migration and differentiation, and this suggests that the mechanics of the adhesion substrate may regulate a cell's ability to uptake exogeneous signalling molecules. In this report, we present a critical role for the rigidity of the cell adhesion substrate on the level of gene transfer and expression. The mechanism relates to material control over cell proliferation, and was investigated using a fluorescent resonance energy transfer (FRET) technique. This study provides a new material-based control point for non-viral gene therapy.

An Integrin from Shrimp Litopenaeus vannamei Mediated Microbial Agglutination and Cell Proliferation

PubMed Central

Zhang, Ying; Wang, Leilei; Wang, Lingling; Wu, Ning; Zhou, Zhi; Song, Linsheng

2012-01-01

Background Integrins are a family of adhesion receptors which regulate cell proliferation, differentiation, leukocyte migration, and complement receptor-dependent phagocytosis. In invertebrates, as a cell adhesion receptor, β integrins play an important role for the balanced activation of immune defense responses especially during the encounter of infections. The present study attempts to characterize the immune functions of shrimp integrin (LvIntegrin) to have better understanding on the immune system and its regulation mechanisms in shrimps. Methodology A shrimp integrin was identified from the Pacific white shrimp Litopenaeus vannamei (designated as LvIntegrin). Its full-length cDNA was of 2621 bp with an open reading frame (ORF) of 2439 bp encoding a polypeptide of 812 amino acids. The mRNA expression of LvIntegrin was significantly up-regulated at 3, 6 and 12 h after Listonella anguillarum challenge. The cDNA fragment encoding β integrin domains (βA and hybrid domain) of LvIntegrin was recombined and expressed in Escherichia coli BL21(DE3)-pLysS. The recombinant protein (rLvIntegrin) could significantly agglutinate the tested microbe including E. coli JM109, L. anguillarum, Micrococcus luteus and Candida dattiladattila in the presence of divalent cations. Moreover, when NIH3T3 cells were cultured with rLvIntegrin, the proliferation rate increased significantly in a dose-dependent manner. Conclusions LvIntegrin, a shrimp β integrin was identified from L. vannamei, shared several highly conserved features. LvIntegrin exhibited broad-spectrum agglutination activity towards both bacteria and fungi and could improve the proliferation of NIH3T3 cells, indicating that LvIntegrin is involved in the immune response against microbe challenge and regulation of cell proliferation as a cell adhesion receptor in shrimp. PMID:22792387

An integrin from shrimp Litopenaeus vannamei mediated microbial agglutination and cell proliferation.

PubMed

Zhang, Ying; Wang, Leilei; Wang, Lingling; Wu, Ning; Zhou, Zhi; Song, Linsheng

2012-01-01

Integrins are a family of adhesion receptors which regulate cell proliferation, differentiation, leukocyte migration, and complement receptor-dependent phagocytosis. In invertebrates, as a cell adhesion receptor, β integrins play an important role for the balanced activation of immune defense responses especially during the encounter of infections. The present study attempts to characterize the immune functions of shrimp integrin (LvIntegrin) to have better understanding on the immune system and its regulation mechanisms in shrimps. A shrimp integrin was identified from the Pacific white shrimp Litopenaeus vannamei (designated as LvIntegrin). Its full-length cDNA was of 2621 bp with an open reading frame (ORF) of 2439 bp encoding a polypeptide of 812 amino acids. The mRNA expression of LvIntegrin was significantly up-regulated at 3, 6 and 12 h after Listonella anguillarum challenge. The cDNA fragment encoding β integrin domains (βA and hybrid domain) of LvIntegrin was recombined and expressed in Escherichia coli BL21(DE3)-pLysS. The recombinant protein (rLvIntegrin) could significantly agglutinate the tested microbe including E. coli JM109, L. anguillarum, Micrococcus luteus and Candida dattiladattila in the presence of divalent cations. Moreover, when NIH3T3 cells were cultured with rLvIntegrin, the proliferation rate increased significantly in a dose-dependent manner. LvIntegrin, a shrimp β integrin was identified from L. vannamei, shared several highly conserved features. LvIntegrin exhibited broad-spectrum agglutination activity towards both bacteria and fungi and could improve the proliferation of NIH3T3 cells, indicating that LvIntegrin is involved in the immune response against microbe challenge and regulation of cell proliferation as a cell adhesion receptor in shrimp.

Peptide-decorated chitosan derivatives enhance fibroblast adhesion and proliferation in wound healing.

PubMed

Patrulea, V; Hirt-Burri, N; Jeannerat, A; Applegate, L A; Ostafe, V; Jordan, O; Borchard, G

2016-05-20

RGD peptide sequences are known to regulate cellular activities by interacting with α5β1, αvβ5 and αvβ3 integrin, which contributes to the wound healing process. In this study, RGDC peptide was immobilized onto chitosan derivative 1,6-diaminohexane-O-carboxymethyl-N,N,N-trimethyl chitosan (DAH-CMTMC) to display RGDC-promoting adhesion for enhanced wound healing. The efficiency of N-methylation, O-carboxymethylation and spacer grafting was quantitatively and qualitatively analyzed by (1)H NMR and FTIR, yielding 0.38 degree of substitution for N-methylation and >0.85 for O-carboxymethylation. The glass transition temperatures for chitosan derivatives were also studied. Peptide immobilization was achieved through sulfhydryl groups using sulfosuccinimidyl (4-iodoacetyl)amino-benzoate (sulfo-SIAB method). RGDC immobilized peptide onto DAH-CMTMC was found to be about 15.3 μg/mg of chitosan derivative by amino acid analysis (AAA). The significant increase of human dermal fibroblast (HDF) viability in vitro over 7 days suggests that RGDC-functionalized chitosan may lead to enhanced wound healing (viability >140%). Moreover, bio-adhesion and proliferation assays confirmed that coatings of RGDC-functionalized chitosan derivatives exhibit in vitro wound healing properties by enhancing fibroblast proliferation and adhesion. These results showed that RGDC peptide-functionalized chitosan provides an optimal environment for fibroblast adhesion and proliferation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Discoidin domain receptor 2 (DDR2) regulates proliferation of endochondral cells in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawai, Ikuma; Hisaki, Tomoka; Sugiura, Koji

2012-10-26

Highlights: Black-Right-Pointing-Pointer Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase. Black-Right-Pointing-Pointer DDR2 regulates cell proliferation, cell adhesion, migration, and extracellular matrix remodeling. Black-Right-Pointing-Pointer We produced in vitro and in vivo model to better understand the role of DDR2. Black-Right-Pointing-Pointer DDR2 might play an inhibitory role in the proliferation of chondrocyte. -- Abstract: Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase that is activated by fibrillar collagens. DDR2 regulates cell proliferation, cell adhesion, migration, and extracellular matrix remodeling. The decrement of endogenous DDR2 represses osteoblastic marker gene expression and osteogenic differentiation in murine preosteoblastic cells, but themore » functions of DDR2 in chondrogenic cellular proliferation remain unclear. To better understand the role of DDR2 signaling in cellular proliferation in endochondral ossification, we inhibited Ddr2 expression via the inhibitory effect of miRNA on Ddr2 mRNA (miDdr2) and analyzed the cellular proliferation and differentiation in the prechondrocyte ATDC5 cell lines. To investigate DDR2's molecular role in endochondral cellular proliferation in vivo, we also produced transgenic mice in which the expression of truncated, kinase dead (KD) DDR2 protein is induced, and evaluated the DDR2 function in cellular proliferation in chondrocytes. Although the miDdr2-transfected ATDC5 cell lines retained normal differentiation ability, DDR2 reduction finally promoted cellular proliferation in proportion to the decreasing ratio of Ddr2 expression, and it also promoted earlier differentiation to cartilage cells by insulin induction. The layer of hypertrophic chondrocytes in KD Ddr2 transgenic mice was not significantly thicker than that of normal littermates, but the layer of proliferative chondrocytes in KD-Ddr2 transgenic mice was significantly thicker than that of normal

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

PubMed

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.

Mapping cell surface adhesion by rotation tracking and adhesion footprinting

NASA Astrophysics Data System (ADS)

Li, Isaac T. S.; Ha, Taekjip; Chemla, Yann R.

2017-03-01

Rolling adhesion, in which cells passively roll along surfaces under shear flow, is a critical process involved in inflammatory responses and cancer metastasis. Surface adhesion properties regulated by adhesion receptors and membrane tethers are critical in understanding cell rolling behavior. Locally, adhesion molecules are distributed at the tips of membrane tethers. However, how functional adhesion properties are globally distributed on the individual cell’s surface is unknown. Here, we developed a label-free technique to determine the spatial distribution of adhesive properties on rolling cell surfaces. Using dark-field imaging and particle tracking, we extract the rotational motion of individual rolling cells. The rotational information allows us to construct an adhesion map along the contact circumference of a single cell. To complement this approach, we also developed a fluorescent adhesion footprint assay to record the molecular adhesion events from cell rolling. Applying the combination of the two methods on human promyelocytic leukemia cells, our results surprisingly reveal that adhesion is non-uniformly distributed in patches on the cell surfaces. Our label-free adhesion mapping methods are applicable to the variety of cell types that undergo rolling adhesion and provide a quantitative picture of cell surface adhesion at the functional and molecular level.

Polyelectrolyte Multilayer-Treated Electrodes for Real-Time Electronic Sensing of Cell Proliferation

PubMed Central

Mijares, Geraldine I.; Reyes, Darwin R.; Geist, Jon; Gaitan, Michael; Polk, Brian J.; DeVoe, Don L.

2010-01-01

We report on the use of polyelectrolyte multilayer (PEM) coatings as a non-biological surface preparation to facilitate uniform cell attachment and growth on patterned thin-film gold (Au) electrodes on glass for impedance-based measurements. Extracellular matrix (ECM) proteins are commonly utilized as cell adhesion promoters for electrodes; however, they exhibit degradation over time, thereby imposing limitations on the duration of conductance-based biosensor experiments. The motivation for the use of PEM coatings arises from their long-term surface stability as promoters for cell attachment, patterning, and culture. In this work, a cell proliferation monitoring device was fabricated. It consisted of thin-film Au electrodes deposited with a titanium-tungsten (TiW) adhesion layer that were patterned on a glass substrate and passivated to create active electrode areas. The electrode surfaces were then treated with a poly(ethyleneimine) (PEI) anchoring layer and subsequent bilayers of sodium poly(styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH). NIH-3T3 mouse embryonic fibroblast cells were cultured on the device, observed by optical microscopy, and showed uniform growth characteristics similar to those observed on a traditional polystyrene cell culture dish. The optical observations were correlated to electrical measurements on the PEM-treated electrodes, which exhibited a rise in impedance with cell proliferation and stabilized to an approximate 15 % increase as the culture approached confluency. In conclusion, cells proliferate uniformly over gold and glass PEM-treated surfaces, making them useful for continuous impedance-based, real-time monitoring of cell proliferation and for the determination of cell growth rate in cellular assays. PMID:27134780

Peptide modified nanofibrous scaffold promotes human mesenchymal stem cell proliferation and long-term passaging.

PubMed

Mobasseri, Rezvan; Tian, Lingling; Soleimani, Masoud; Ramakrishna, Seeram; Naderi-Manesh, Hossein

2018-03-01

Long-term culture, passage and proliferation of human mesenchymal stem cells (hMSCs) cause loss of their stemness properties including self-renewal and multipotency. By optimizing the MSCs environment in vitro, maintaining the stemness state and better controlling the cell fate might be possible. We have recently reported the significant effects of bioactive Tat protein-derived peptide named R-peptide on hMSC adhesion, morphology and proliferation, which has demonstrated R-peptide enhanced MSC early adhesion and proliferation in comparison to other bioactive molecules including RGD peptide, fibronectin and collagen. In this study, R-peptide was used to evaluate stemness properties of MSCs after long-term passaging. R-peptide conjugated poly caprolactone (PCL) nanofibrous scaffold and unmodified nanofibrous scaffold were used to study the impact of R-peptide modified PCL nanofibers and PCL nanofibers on cell behavior. The results showed early formation of focal adhesion (FA) complex on R-peptide modified scaffolds at 30min after cell seeding. The rate of cell proliferation was significantly increased due to presence of R-peptide, and the MSCs marker analyses using flow cytometry and immunocytochemistry staining proved the ability of R-peptide to maintain mesenchymal stem cell properties (high proliferation, expression of multipotent markers and differentiation capacity) even after long-term passage culturing. Accordingly, our (The) results concluded that bioactive R-peptide in combination with nanofibrous scaffold can mimic the native ECM comprising micro/nano architecture and biochemical molecules in a best way. The designed scaffold can link extracellular matrix (ECM) to nucleus via formation of FA and organization of cytoskeleton, causing fast and strong attachment of MSCs and allowing integrin-mediated signaling to start. Copyright © 2017 Elsevier B.V. All rights reserved.

E-cadherin interactions regulate beta-cell proliferation in islet-like structures.

PubMed

Carvell, Melanie J; Marsh, Phil J; Persaud, Shanta J; Jones, Peter M

2007-01-01

Islet function is dependent on cells within the islet interacting with each other. E-cadherin (ECAD) mediates Ca(2+)-dependent homophilic cell adhesion between b-cells within islets and has been identified as a tumour suppressor. We generated clones of the MIN6 beta-cell line that stably over- (S) and under-express (alphaS) ECAD. Modified expression of ECAD was confirmed by quantitative RT-PCR, immunoblotting and immunocytochemistry. Preproinsulin mRNA, insulin content and basal rates of insulin secretion were higher in S cells compared to aS and control (V) cells. However, stimulated insulin secretory responses were unaffected by ECAD expression levels. ECAD expression did affect proliferation, with enhanced ECAD expression being associated with reduced proliferation and vice versa. Formation of islet-like structures was associated with a significant reduction in proliferation of V and S cells but not alphaS cells. These data suggest that ECAD expression levels do not modulate insulin secretory function but are consistent with a role for ECAD in the regulation of beta-cell proliferation. Copyright (c) 2007 S. Karger AG, Basel.

Lubricin: A novel means to decrease bacterial adhesion and proliferation

PubMed Central

Aninwene, George E.; Abadian, Pegah N.; Ravi, Vishnu; Taylor, Erik N.; Hall, Douglas M.; Mei, Amy; Jay, Gregory D.; Goluch, Edgar D.; Webster, Thomas J.

2015-01-01

This study investigated the ability of lubricin (LUB) to prevent bacterial attachment and proliferation on model tissue culture polystyrene surfaces. The findings from this study indicated that LUB was able to reduce the attachment and growth of Staphylococcus aureus on tissue culture polystyrene over the course of 24 h by approximately 13.9% compared to a phosphate buffered saline (PBS)-soaked control. LUB also increased S. aureus lag time (the period of time between the introduction of bacteria to a new environment and their exponential growth) by approximately 27% compared to a PBS-soaked control. This study also indicated that vitronectin (VTN), a protein homologous to LUB, reduced bacterial S. aureus adhesion and growth on tissue culture polystyrene by approximately 11% compared to a PBS-soaked control. VTN also increased the lag time of S. aureus by approximately 43%, compared to a PBS-soaked control. Bovine submaxillary mucin was studied because there are similarities between it and the center mucin-like domain of LUB. Results showed that the reduction of S. aureus and Staphylococcus epidermidis proliferation on mucin coated surfaces was not as substantial as that seen with LUB. In summary, this study provided the first evidence that LUB reduced the initial adhesion and growth of both S. aureus and S. epidermidis on a model surface to suppress biofilm formation. These reductions in initial bacteria adhesion and proliferation can be beneficial for medical implants and, although requiring more study, can lead to drastically improved patient outcomes. PMID:24737699

Marine Bacterial Polysaccharide EPS11 Inhibits Cancer Cell Growth via Blocking Cell Adhesion and Stimulating Anoikis

PubMed Central

Cao, Ruobing; Jin, Weihua; Shan, Yeqi; Wang, Ju; Liu, Ge; Kuang, Shan

2018-01-01

Tumor cells that acquire metastatic potential have developed resistance to anoikis, a cell death process, after detachment from their primary site to the second organ. In this study, we investigated the molecular mechanisms of a novel marine bacterial polysaccharide EPS11 which exerts its cytotoxic effects through affecting cancer cell adhesion and anoikis. Firstly, we found that EPS11 could significantly affect cell proliferation and block cell adhesion in A549 cells. We further demonstrated that the expression of several cell adhesion associated proteins is downregulated and the filiform structures of cancer cells are destroyed after EPS11 treatment. Interestingly, the destruction of filiform structures in A549 cells by EPS11 is in a dose-dependent manner, and the inhibitory tendency is very consistent with that observed in the cell adhesion assay, which confirms that filiform structures play important roles in modulating cell adhesion. Moreover, we showed that EPS11 induces apoptosis of A549 cells through stimulating βIII-tubulin associated anoikis: (i) EPS11 inhibits the expression of βIII-tubulin in both transcription and translation levels; and (ii) EPS11 treatment dramatically decreases the phosphorylation of protein kinase B (PKB or AKT), a critical downstream effector of βIII-tubulin. Importantly, EPS11 evidently inhibits the growth of A549-derived tumor xenografts in vivo. Thus, our results suggest that EPS11 may be a potential candidate for human non-small cell lung carcinoma treatment via blocking filiform structure mediated adhesion and stimulating βIII-tubulin associated anoikis. PMID:29518055

Nanocarbon Allotropes-Graphene and Nanocrystalline Diamond-Promote Cell Proliferation.

PubMed

Verdanova, Martina; Rezek, Bohuslav; Broz, Antonin; Ukraintsev, Egor; Babchenko, Oleg; Artemenko, Anna; Izak, Tibor; Kromka, Alexander; Kalbac, Martin; Hubalek Kalbacova, Marie

2016-05-01

Two profoundly different carbon allotropes - nanocrystalline diamond and graphene - are of considerable interest from the viewpoint of a wide range of biomedical applications including implant coating, drug and gene delivery, cancer therapy, and biosensing. Osteoblast adhesion and proliferation on nanocrystalline diamond and graphene are compared under various conditions such as differences in wettability, topography, and the presence or absence of protein interlayers between cells and the substrate. The materials are characterized in detail by means of scanning electron microscopy, atomic force microscopy, photoelectron spectroscopy, Raman spectroscopy, and contact angle measurements. In vitro experiments have revealed a significantly higher degree of cell proliferation on graphene than on nanocrystalline diamond and a tissue culture polystyrene control material. Proliferation is promoted, in particular, by hydrophobic graphene with a large number of nanoscale wrinkles independent of the presence of a protein interlayer, i.e., substrate fouling is not a problematic issue in this respect. Nanowrinkled hydrophobic graphene, thus, exhibits superior characteristics for those biomedical applications where high cell proliferation is required under differing conditions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Heme oxygenase-1 protects INF-gamma primed endothelial cells from Jurkat T-cell adhesion.

PubMed

Du, D; Chang, S; Chen, B; Zhou, H; Chen, Z K

2007-12-01

The heme oxygenase-1 (HO-1) system is associated with the rate-limiting step of conversion of heme, one of the most critical roles in cytoprotective mechanisms. Our study investigated its potential role in protection of endothelial cells from T cells. The recombinant plasmid pcDNA3-HO-1 was transfected into endothelial cells. Indirect fluorescent staining was used to examine the expression of HO-1 protein. Then endothelial cells primed by INF-gamma were mixed in culture with Jurkat T cells labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE). The number of adhesive Jurkat T cells was determined using FACS to evaluate the adhesion effect. After being cultured with endothelial cells, the cell cycle of Jurkat T cells was detected using FACS. Expression of HO-1 on endothelial cells conferred significant protection against Jurkat T-cell-mediated adhesion. The rate of Jurkat T-cell adhesions was reduced to 19.06%, in contrast with 31.42% in the control group (P<.05). After using ZnPP, an inhibitor of HO-1, the rate of Jurkat T-cell adhesion recovered to 29.08%. The binding activities between endothelial cells and Jurkat T cells was blocked by HO-1 expression. The proliferation of Jurkat T cells was inhibited after culture with endothelial cells, which had been transfected with HO-1, which blocked cell cycle entry of T cells. More than 60% of Jurkat T cells remained in G0/G1 compared with 40% among the control group. HO-1 directly protected endothelial cells primed by INF-gamma from Jurkat T cells and down-regulated the expression of HLA-DR on the surface of endothelial cells. These results indicated that transgenic expression of HO-1 may be useful to prevent lymphocytes from responding to endothelial cells.

LGR5 receptor promotes cell-cell adhesion in stem cells and colon cancer cells via the IQGAP1-Rac1 pathway.

PubMed

Carmon, Kendra S; Gong, Xing; Yi, Jing; Wu, Ling; Thomas, Anthony; Moore, Catherine M; Masuho, Ikuo; Timson, David J; Martemyanov, Kirill A; Liu, Qingyun J

2017-09-08

Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) is a bona fide marker of adult stem cells in several epithelial tissues, most notably in the intestinal crypts, and is highly up-regulated in many colorectal, hepatocellular, and ovarian cancers. LGR5 activation by R-spondin (RSPO) ligands potentiates Wnt/β-catenin signaling in vitro ; however, deletion of LGR5 in stem cells has little or no effect on Wnt/β-catenin signaling or cell proliferation in vivo Remarkably, modulation of LGR5 expression has a major impact on the actin cytoskeletal structure and cell adhesion in the absence of RSPO stimulation, but the molecular mechanism is unclear. Here, we show that LGR5 interacts with IQ motif-containing GTPase-activating protein 1 (IQGAP1), an effector of Rac1/CDC42 GTPases, in the regulation of actin cytoskeleton dynamics and cell-cell adhesion. Specifically, LGR5 decreased levels of IQGAP1 phosphorylation at Ser-1441/1443, leading to increased binding of Rac1 to IQGAP1 and thus higher levels of cortical F-actin and enhanced cell-cell adhesion. LGR5 ablation in colon cancer cells and crypt stem cells resulted in loss of cortical F-actin, reduced cell-cell adhesion, and disrupted localization of adhesion-associated proteins. No evidence of LGR5 coupling to any of the four major subtypes of heterotrimeric G proteins was found. These findings suggest that LGR5 primarily functions via the IQGAP1-Rac1 pathway to strengthen cell-cell adhesion in normal adult crypt stem cells and colon cancer cells. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

The shed ectodomain of Nr-CAM stimulates cell proliferation and motility, and confers cell transformation.

PubMed

Conacci-Sorrell, Maralice; Kaplan, Anna; Raveh, Shani; Gavert, Nancy; Sakurai, Takeshi; Ben-Ze'ev, Avri

2005-12-15

Nr-CAM, a cell-cell adhesion molecule of the immunoglobulin-like cell adhesion molecule family, known for its function in neuronal outgrowth and guidance, was recently identified as a target gene of beta-catenin signaling in human melanoma and colon carcinoma cells and tissue. Retrovirally mediated transduction of Nr-CAM into fibroblasts induces cell motility and tumorigenesis. We investigated the mechanisms by which Nr-CAM can confer properties related to tumor cell behavior and found that Nr-CAM expression in NIH3T3 cells protects cells from apoptosis in the absence of serum by constitutively activating the extracellular signal-regulated kinase and AKT signaling pathways. We detected a metalloprotease-mediated shedding of Nr-CAM into the culture medium of cells transfected with Nr-CAM, and of endogenous Nr-CAM in B16 melanoma cells. Conditioned medium and purified Nr-CAM-Fc fusion protein both enhanced cell motility, proliferation, and extracellular signal-regulated kinase and AKT activation. Moreover, Nr-CAM was found in complex with alpha4beta1 integrins in melanoma cells, indicating that it can mediate, in addition to homophilic cell-cell adhesion, heterophilic adhesion with extracellular matrix receptors. Suppression of Nr-CAM levels by small interfering RNA in B16 melanoma inhibited the adhesive and tumorigenic capacities of these cells. Stable expression of the Nr-CAM ectodomain in NIH3T3 cells conferred cell transformation and tumorigenesis in mice, suggesting that the metalloprotease-mediated shedding of Nr-CAM is a principal route for promoting oncogenesis by Nr-CAM.

Adhesion and proliferation of fibroblasts on RF plasma-deposited nanostructured fluorocarbon coatings: evidence of FAK activation.

PubMed

Rosso, Francesco; Marino, Gerardo; Muscariello, Livio; Cafiero, Gennaro; Favia, Pietro; D'Aloia, Erica; d'Agostino, Riccardo; Barbarisi, Alfonso

2006-06-01

We used combined plasma-deposition process to deposit smooth and nanostructured fluorocarbon coatings on polyethylenethereftalate (PET) substrates, to obtain surfaces with identical chemical composition and different roughness, and investigate the effect of surface nanostructures on adhesion and proliferation of 3T3 Swiss Albino Mouse fibroblasts. Untreated PET and polystyrene (PS) were used as controls for cell culture. We have found that the statistically significant increase of cell proliferation rate and FAK (a nonreceptor tyrosine kinase) activation detected on ROUGH fluorocarbon surfaces is due to the presence of nanostructures. Changes in cytoskeletal organization and phospho FAK (tyr 397) localization were evident after 60 min on cells adhering to ROUGH surfaces. This change was characterized by the formation of actin stress fibers along lamellar membrane protrusion instead of usual focal contacts. Also the morphology of the adhering fibroblasts (60 min) adhering on ROUGH surfaces was found quite different compared to cells adhering on smooth ones. Copyright 2006 Wiley-Liss, Inc.

Analytical cell adhesion chromatography reveals impaired persistence of metastatic cell rolling adhesion to P-selectin

PubMed Central

Oh, Jaeho; Edwards, Erin E.; McClatchey, P. Mason; Thomas, Susan N.

2015-01-01

ABSTRACT Selectins facilitate the recruitment of circulating cells from the bloodstream by mediating rolling adhesion, which initiates the cell–cell signaling that directs extravasation into surrounding tissues. To measure the relative efficiency of cell adhesion in shear flow for in vitro drug screening, we designed and implemented a microfluidic-based analytical cell adhesion chromatography system. The juxtaposition of instantaneous rolling velocities with elution times revealed that human metastatic cancer cells, but not human leukocytes, had a reduced capacity to sustain rolling adhesion with P-selectin. We define a new parameter, termed adhesion persistence, which is conceptually similar to migration persistence in the context of chemotaxis, but instead describes the capacity of cells to resist the influence of shear flow and sustain rolling interactions with an adhesive substrate that might modulate the probability of extravasation. Among cell types assayed, adhesion persistence to P-selectin was specifically reduced in metastatic but not leukocyte-like cells in response to a low dose of heparin. In conclusion, we demonstrate this as an effective methodology to identify selectin adhesion antagonist doses that modulate homing cell adhesion and engraftment in a cell-subtype-selective manner. PMID:26349809

The evaluation of p,p'-DDT exposure on cell adhesion of hepatocellular carcinoma.

PubMed

Jin, Xiaoting; Chen, Meilan; Song, Li; Li, Hanqing; Li, Zhuoyu

2014-08-01

Many studies have found a positive association between the progression of hepatocellular carcinoma and DDT exposure. These studies mainly focus on the effect of DDT exposure on cell proliferation and epithelial to mesenchymal transition (EMT) promotion. However, the influence of DDT on cell adhesion of hepatocellular carcinoma remains to be unclear. The aim of our study was to determine the effect of p,p'-DDT on cell adhesion of hepatocellular carcinoma in vitro and in vivo. The data showed that p,p'-DDT, exposing HepG2 cells for 6 days, decreased cell-cell adhesion and elevated cell-matrix adhesion. Strikingly, p,p'-DDT increased reactive oxygen species (ROS) content, and this was accompanied by the activation of JAK/STAT3 pathway. Moreover, ROS inhibitor supplement reversed these effects significantly. However, the addition of ER inhibitor, ICI, had no effect on the p,p'-DDT-induced effects. p,p'-DDT altered the mRNA levels of related adhesion molecules, including inhibition of E-cadherin and promotion of N-cadherin along with CD29. Interestingly, the p,p'-DDT-altered adhesion molecules could be reversed with JAK inhibitor or STAT3 inhibitor. Likewise, p,p'-DDT stimulated the JAK/STAT3 pathway in nude mice, as well as altered the mRNA levels of E-cadherin, N-cadherin, and CD29. Taken together, these results indicate that p,p'-DDT profoundly promotes the adhesion process by decreasing cell-cell adhesion and inducing cell-matrix adhesion via the ROS-mediated JAK/STAT3 pathway. All these events account for the carcinogenic potential of p,p'-DDT in liver. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Twist1-positive epithelial cells retain adhesive and proliferative capacity throughout dissemination

PubMed Central

Shamir, Eliah R.; Coutinho, Kester; Georgess, Dan; Auer, Manfred

2016-01-01

ABSTRACT Dissemination is the process by which cells detach and migrate away from a multicellular tissue. The epithelial-to-mesenchymal transition (EMT) conceptualizes dissemination in a stepwise fashion, with downregulation of E-cadherin leading to loss of intercellular junctions, induction of motility, and then escape from the epithelium. This gain of migratory activity is proposed to be mutually exclusive with proliferation. We previously developed a dissemination assay based on inducible expression of the transcription factor Twist1 and here utilize it to characterize the timing and dynamics of intercellular adhesion, proliferation and migration during dissemination. Surprisingly, Twist1+ epithelium displayed extensive intercellular junctions, and Twist1– luminal epithelial cells could still adhere to disseminating Twist1+ cells. Although proteolysis and proliferation were both observed throughout dissemination, neither was absolutely required. Finally, Twist1+ cells exhibited a hybrid migration mode; their morphology and nuclear deformation were characteristic of amoeboid cells, whereas their dynamic protrusive activity, pericellular proteolysis and migration speeds were more typical of mesenchymal cells. Our data reveal that epithelial cells can disseminate while retaining competence to adhere and proliferate. PMID:27402962

Adhesion and migration of CHO cells on micropatterned single layer graphene

NASA Astrophysics Data System (ADS)

Keshavan, S.; Oropesa-Nuñez, R.; Diaspro, A.; Canale, C.; Dante, S.

2017-06-01

Cell patterning technology on single layer graphene (SLG) is a fairly new field that can find applications in tissue engineering and biomaterial/biosensors development. Recently, we have developed a simple and effective approach for the fabrication of patterned SLG substrates by laser micromachining, and we have successfully applied it for the obtainment of geometrically ordered neural networks. Here, we exploit the same approach to investigate the generalization of the cell response to the surface cues of the fabricated substrates and, contextually, to quantify cell adhesion on the different areas of the patterns. To attain this goal, we tested Chinese hamster ovary (CHO) cells on PDL-coated micropatterned SLG substrates and quantified the adhesion by using single cell force spectroscopy (SCFS). Our results indicate higher cell adhesion on PDL-SLG, and, consequently, an initial CHO cell accumulation on the graphene areas, confirming the neuronal behaviour observed previously; interestingly, at later time point in culture, cell migration was observed towards the adjacent SLG ablated regions, which resulted more favourable for cell proliferation. Therefore, our findings indicate that the mechanism of interaction with the surface cues offered by the micropatterned substrates is strictly cell-type dependent.

Controlling the cell adhesion property of silk films by graft polymerization.

PubMed

Dhyani, Vartika; Singh, Neetu

2014-04-09

We report here a graft polymerization method to improve the cell adhesion property of Bombyx mori silk fibroin films. B. mori silk has evolved as a promising material for tissue engineering because of its biocompatibility and biodegradability. However, silk's hydrophobic character makes cell adhesion and proliferation difficult. Also, the lack of sufficient reactive amino acid residues makes biofunctionalization via chemical modification challenging. Our study describes a simple method that provides increased chemical handles for tuning of the surface chemistry of regenerated silk films (SFs), thus allowing manipulation of their bioactivity. By grafting pAAc and pHEMA via plasma etching, we have increased carboxylic acid and hydroxyl groups on silk, respectively. These modifications allowed us to tune the hydrophilicity of SFs and provide functional groups for bioconjugation. Our strategy also allowed us to develop silk-based surface coatings, where spatial control over cell adhesion can be achieved. This control over cell adhesion in a particular region of the SFs is difficult to obtain via existing methods of modifying the silk fibroin instead of the SF surface. Thus, our strategy will be a valuable addition to the toolkit of biofunctionalization for enhancing SFs' tissue engineering applications.

Intercellular adhesion molecule-1 expression by skeletal muscle cells augments myogenesis.

PubMed

Goh, Qingnian; Dearth, Christopher L; Corbett, Jacob T; Pierre, Philippe; Chadee, Deborah N; Pizza, Francis X

2015-02-15

We previously demonstrated that the expression of intercellular adhesion molecule-1 (ICAM-1) by skeletal muscle cells after muscle overload contributes to ensuing regenerative and hypertrophic processes in skeletal muscle. The objective of the present study is to reveal mechanisms through which skeletal muscle cell expression of ICAM-1 augments regenerative and hypertrophic processes of myogenesis. This was accomplished by genetically engineering C2C12 myoblasts to stably express ICAM-1, and by inhibiting the adhesive and signaling functions of ICAM-1 through the use of a neutralizing antibody or cell penetrating peptide, respectively. Expression of ICAM-1 by cultured skeletal muscle cells augmented myoblast-myoblast adhesion, myotube formation, myonuclear number, myotube alignment, myotube-myotube fusion, and myotube size without influencing the ability of myoblasts to proliferate or differentiate. ICAM-1 augmented myotube formation, myonuclear accretion, and myotube alignment through a mechanism involving adhesion-induced activation of ICAM-1 signaling, as these dependent measures were reduced via antibody and peptide inhibition of ICAM-1. The adhesive and signaling functions of ICAM-1 also facilitated myotube hypertrophy through a mechanism involving myotube-myotube fusion, protein synthesis, and Akt/p70s6k signaling. Our findings demonstrate that ICAM-1 expression by skeletal muscle cells augments myogenesis, and establish a novel mechanism through which the inflammatory response facilitates growth processes in skeletal muscle. Copyright © 2014 Elsevier Inc. All rights reserved.

Intercellular Adhesion Molecule-1 Expression by Skeletal Muscle Cells Augments Myogenesis

PubMed Central

Goh, Qingnian; Dearth, Christopher L.; Corbett, Jacob T.; Pierre, Philippe; Chadee, Deborah N.; Pizza, Francis X.

2014-01-01

We previously demonstrated that the expression of intercellular adhesion molecule-1 (ICAM-1) by skeletal muscle cells after muscle overload contributes to ensuing regenerative and hypertrophic processes in skeletal muscle. The objective of the present study is to reveal mechanisms through which skeletal muscle cell expression of ICAM-1 augments regenerative and hypertrophic processes of myogenesis. This was accomplished by genetically engineering C2C12 myoblasts to stably express ICAM-1, and by inhibiting the adhesive and signaling functions of ICAM-1 through the use of a neutralizing antibody or cell penetrating peptide, respectively. Expression of ICAM-1 by cultured skeletal muscle cells augmented myoblast-myoblast adhesion, myotube formation, myonuclear number, myotube alignment, myotube-myotube fusion, and myotube size without influencing the ability of myoblasts to proliferate or differentiate. ICAM-1 augmented myotube formation, myonuclear accretion, and myotube alignment through a mechanism involving adhesion-induced activation of ICAM-1 signaling, as these dependent measures were reduced via antibody and peptide inhibition of ICAM-1. The adhesive and signaling functions of ICAM-1 also facilitated myotube hypertrophy through a mechanism involving myotube-myotube fusion, protein synthesis, and Akt/p70s6k signaling. Our findings demonstrate that ICAM-1 expression by skeletal muscle cells augments myogenesis, and establish a novel mechanism through which the inflammatory response facilitates growth processes in skeletal muscle. PMID:25281303

PI3K{gamma} activation by CXCL12 regulates tumor cell adhesion and invasion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Monterrubio, Maria; Mellado, Mario; Carrera, Ana C.

Tumor dissemination is a complex process, in which certain steps resemble those in leukocyte homing. Specific chemokine/chemokine receptor pairs have important roles in both processes. CXCL12/CXCR4 is the most commonly expressed chemokine/chemokine receptor pair in human cancers, in which it regulates cell adhesion, extravasation, metastatic colonization, angiogenesis, and proliferation. All of these processes require activation of signaling pathways that include G proteins, phosphatidylinositol-3 kinase (PI3K), JAK kinases, Rho GTPases, and focal adhesion-associated proteins. We analyzed these pathways in a human melanoma cell line in response to CXCL12 stimulation, and found that PI3K{gamma} regulates tumor cell adhesion through mechanisms different frommore » those involved in cell invasion. Our data indicate that, following CXCR4 activation after CXCL12 binding, the invasion and adhesion processes are regulated differently by distinct downstream events in these signaling cascades.« less

Cell density-dependent differential proliferation of neural stem cells on omnidirectional nanopore-arrayed surface.

PubMed

Cha, Kyoung Je; Kong, Sun-Young; Lee, Ji Soo; Kim, Hyung Woo; Shin, Jae-Yeon; La, Moonwoo; Han, Byung Woo; Kim, Dong Sung; Kim, Hyun-Jung

2017-10-12

Recently, the importance of surface nanotopography in the determination of stem cell fate and behavior has been revealed. In the current study, we generated polystyrene cell-culture dishes with an omnidirectional nanopore arrayed surface (ONAS) (diameter: 200 nm, depth: 500 nm, center-to-center distance: 500 nm) and investigated the effects of nanotopography on rat neural stem cells (NSCs). NSCs cultured on ONAS proliferated better than those on the flat surface when cell density was low and showed less spontaneous differentiation during proliferation in the presence of mitogens. Interestingly, NSCs cultured on ONAS at clonal density demonstrated a propensity to generate neurospheres, whereas those on the flat surface migrated out, proliferated as individuals, and spread out to attach to the surface. However, the differential patterns of proliferation were cell density-dependent since the distinct phenomena were lost when cell density was increased. ONAS modulated cytoskeletal reorganization and inhibited formation of focal adhesion, which is generally observed in NSCs grown on flat surfaces. ONAS appeared to reinforce NSC-NSC interaction, restricted individual cell migration and prohibited NSC attachment to the nanopore surface. These data demonstrate that ONAS maintains NSCs as undifferentiated while retaining multipotency and is a better topography for culturing low density NSCs.

Galectin-1 induces cell adhesion to the extracellular matrix and apoptosis of non-adherent human colon cancer Colo201 cells.

PubMed

Horiguchi, Natsuko; Arimoto, Kei-ichiro; Mizutani, Atsushi; Endo-Ichikawa, Yoko; Nakada, Hiroshi; Taketani, Shigeru

2003-12-01

To isolate cDNAs for molecules involved in cell adhesion to the extracellular matrix, expression cloning with non-adherent colon cancer Colo201 cells was carried out. Four positive clones were isolated and, when sequenced, one was found to be galectin-1, a beta-galactoside-binding protein. When cultured on fibronectin-, laminin-, and collagen-coated and non-coated dishes, the adherent galectin-1 cDNA-transfected Colo201 cells increased and spread somewhat. Immunofluorescence staining revealed that galectin-1 was expressed inside and outside of Colo201 cells. The adhesion was dependent on the carbohydrate-recognition domain of galectin-1 since lactose inhibited the adhesion and exogenously-added galectin-1 caused the adhesion. PD58059, an inhibitor of mitogen-activated protein kinase, or LY294002, a phosphoinositide 3-OH kinase inhibitor, decreased the adhesion. Furthermore, the expression of galectin-1 in Colo201 cells induced apoptotic cell death, while exogenously-added galectin-1 did not cause apoptosis. These results indicate that galectin-1 plays a role in both cell-matrix interactions and the inhibition of Colo201 cell proliferation, and suggest that galectin-1 expressed in cells could be associated with apoptosis.

Self assembling bioactive materials for cell adhesion in tissue repair

NASA Astrophysics Data System (ADS)

Hwang, Julia J.

This work involved the study of biodegradable and biocompatible materials that have the potential to modify tissue engineering scaffolds through self assembly, generating multiple layers that deliver bioactivity. Diblock biomaterials containing cholesteryl moieties and oligomers of lactic acid units were found to form single crystals when precipitated from hot ethanol and smectic liquid crystalline phases when cast as a film. Cell culture experiments on these films with 3T3 and 3T6 fibroblasts indicated that these ordered materials form surfaces with specific chemistries that favored cell adhesion, spreading, and proliferation suggesting the potential of mediating human tissue repair. The author believes the cholesteryl moieties found on the surface play a key role in determining cell behavior. Cholesteryl-(L-lactic acid) diblock molecules were then functionalized with moieties including vitamin Bx, cholesterol, and the anti-inflammatory drug indomethacin. An unstable activated ester between indomethacin and the diblock molecule resulted in the release of indomethacin into the culture medium which inhibited the proliferation of 3T3 fibroblasts. Finally, a series of molecules were designed to incorporate dendrons based on amino acids at the termini of the diblock structures. It was determined that lysine, a basic amino acid, covalently coupled to cholesteryl-(L-lactic acid) can promote cell adhesion and spreading while negatively charged and zwitterionic 2nd generation dendrons based on aspartic acid do not. Incorporation of the well known arginine-glycine-aspartic acid (RGD) sequence, which is found in many adhesive proteins, to the dendrons imparted integrin-mediated cell adhesion as evidenced by the formation of stress fibers. We also explored the capacity of integrin receptors to bind to ligands that are not the linear form of RGD, but have R, G, and D spatially positioned to mimic the linear RGD environments. For this purpose, the arms of the 2 nd generation

Effects of decellularized matrices derived from periodontal ligament stem cells and SHED on the adhesion, proliferation and osteogenic differentiation of human dental pulp stem cells in vitro.

PubMed

Heng, Boon Chin; Zhu, Shaoyue; Xu, Jianguang; Yuan, Changyong; Gong, Ting; Zhang, Chengfei

2016-04-01

A major bottleneck to the therapeutic applications of dental pulp stem cells (DPSC) are their limited proliferative capacity ex vivo and tendency to undergo senescence. This may be partly due to the sub-optimal in vitro culture milieu, which could be improved by an appropriate extracellular matrix substratum. This study therefore examined decellularized matrix (DECM) from stem cells derived from human exfoliated deciduous teeth (SHED) and periodontal ligament stem cells (PDLSC), as potential substrata for DPSC culture. Both SHED-DECM and PDLSC-DECM promoted rapid adhesion and spreading of newly-seeded DPSC compared to bare polystyrene (TCPS), with vinculin immunocytochemistry showing expression of more focal adhesions by newly-adherent DPSC cultured on DECM versus TCPS. Culture of DPSC on SHED-DECM and PDLSC-DECM yielded higher proliferation of cell numbers compared to TCPS. The qRT-PCR data showed significantly higher expression of nestin by DPSC cultured on DECM versus the TCPS control. Osteogenic differentiation of DPSC was enhanced by culturing on PDLSC-DECM and SHED-DECM versus TCPS, as demonstrated by alizarin red S staining for mineralized calcium deposition, alkaline phosphatase assay and qRT-PCR analysis of key osteogenic marker expression. Hence, both SHED-DECM and PDLSC-DECM could enhance the ex vivo culture of DPSC under both non-inducing and osteogenic-inducing conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Interleukin-8 is associated with adhesion, migration and invasion in human gastric cancer SCG-7901 cells.

PubMed

Ju, Dawei; Sun, Dazhi; Xiu, Lijuan; Meng, Xianze; Zhang, Cian; Wei, Pinkang

2012-03-01

Interleukin-8 is known as an important chemokine involved in tumor angiogenesis and progression. Overexpression of interleukin-8 has been detected in a variety of human tumors, including gastric cancer, and is negatively correlated with prognosis. The aim of our study is to determine the effects of interleukin-8 on proliferation, adhesion, migration and invasion abilities and correlated molecular mechanisms in gastric cancer. We made recombinant interleukin-8 ranged from 0 ng/ml to 100 ng/ml interferes in human gastric cancer SCG-7901 cells in vitro. The results shown that interleukin-8 did not change cell proliferation, but promoted cell adhesion to endothelial cell and extracellular matrix components (collagen, laminin and fibronectin) as detected by Cell Counting Kit-8. And it induced migration and invasion ability based on scratch and transwell-chamber assays. Also, interleukin-8 regulated the protein and mRNA expression of matrix metalloproteinase-9, intercellular adhesion molecule-1 and E-cad and there was obviously a dose-dependent relationship, but the protein or mRNA expression of matrix metalloproteinase-2 was not obviously changed under the tested conditions. Our findings indicate that interleukin-8 is associated with adhesion, migration and invasion in gastric cancer and the regulation of matrix metalloproteinase-9, intercellular adhesion molecule-1 and E-cad expression is one of the potential molecule mechanisms. The studies imply interleukin-8 may be an alternative treatment strategy against gastric cancer.

EGCG Inhibits Proliferation, Invasiveness and Tumor Growth by Up-Regulation of Adhesion Molecules, Suppression of Gelatinases Activity, and Induction of Apoptosis in Nasopharyngeal Carcinoma Cells

PubMed Central

Fang, Chih-Yeu; Wu, Chung-Chun; Hsu, Hui-Yu; Chuang, Hsin-Ying; Huang, Sheng-Yen; Tsai, Ching-Hwa; Chang, Yao; Tsao, George Sai-Wah; Chen, Chi-Long; Chen, Jen-Yang

2015-01-01

(−)-Epigallocatechin-3-gallate (EGCG), a major green tea polyphenol, has been shown to inhibit the proliferation of a variety of tumor cells. Epidemiological studies have shown that drinking green tea can reduce the incidence of nasopharyngeal carcinoma (NPC), yet the underlying mechanism is not well understood. In this study, the inhibitory effect of EGCG was tested on a set of Epstein Barr virus-negative and -positive NPC cell lines. Treatment with EGCG inhibited the proliferation of NPC cells but did not affect the growth of a non-malignant nasopharyngeal cell line, NP460hTert. Moreover, EGCG treated cells had reduced migration and invasive properties. The expression of the cell adhesion molecules E-cadherin and β-catenin was found to be up-regulated by EGCG treatment, while the down-regulation of matrix metalloproteinases (MMP)-2 and MMP-9 were found to be mediated by suppression of extracellular signal-regulated kinase (ERK) phosphorylation and AP-1 and Sp1 transactivation. Spheroid formation by NPC cells in suspension was significantly inhibited by EGCG. Oral administration of EGCG was capable of suppressing tumor growth in xenografted mice bearing NPC tumors. Treatment with EGCG was found to elevate the expression of p53 and p21, and eventually led to apoptosis of NPC cells via caspase 3 activation. The nuclear translocation of NF-κB and β-catenin was also suppressed by EGCG treatment. These results indicate that EGCG can inhibit the proliferation and invasiveness, and induce apoptosis, of NPC cells, making it a promising agent for chemoprevention or adjuvant therapy of NPC. PMID:25625511

Myostatin inhibits proliferation of human urethral rhabdosphincter satellite cells.

PubMed

Akita, Yasuyuki; Sumino, Yasuhiro; Mori, Ken-ichi; Nomura, Takeo; Sato, Fuminori; Mimata, Hiromitsu

2013-05-01

Myostatin, a member of the transforming growth factor-β superfamily, is a negative regulator of myogenesis in skeletal muscle. We examined the effect of myostatin and myostatin inhibition by an antagonistic agent, follistatin, on growth of human urethral rhabdosphincter satellite cells (muscle stem cells) to develop a new strategy for treatment of stress urinary incontinence. Rhabdosphincter satellite cells were cultured and selected by magnetic affinity cell sorting using an anti-neural cell adhesion molecule antibody. The cells were transfected with simian virus-40 antigen to extend their lifespan. A cell proliferation assay, a cell cycle analysis and an investigation of signal transduction were carried out. The autocrine action of endogenous myostatin by western blotting, real-time reverse transcription polymerase chain reaction and immunoneutralization using an anti-myostatin antibody was also evaluated. Selectively cultured cells expressed markers of striated muscles and successfully differentiated into myotubes. Myostatin inhibited proliferation of these cells through Smad2 phosphorylation and cell cycle arrest. Inhibitory effects of myostatin were reversed by addition of follistatin. However, rhabdosphincter satellite cells did not appear to use autocrine secretion of myostatin to regulate their proliferation. Inhibition of myostatin function might be a useful pathway in the development of novel strategies for stimulating rhabdosphincter cells regeneration to treat stress urinary incontinence. © 2012 The Japanese Urological Association.

Enhanced adhesion of osteoblastic cells on polystyrene films by independent control of surface topography and wettability.

PubMed

Yang, Seung Yun; Kim, Eung-Sam; Jeon, Gumhye; Choi, Kwan Yong; Kim, Jin Kon

2013-04-01

We independently controlled surface topography and wettability of polystyrene (PS) films by CF4 and oxygen plasma treatments, respectively, to evaluate the adhesion and proliferation of human fetal osteoblastic (hFOB) cells on the films. Among the CF4 plasma-treated PS films with the average surface roughness ranging from 0.9 to 70 nm, the highest adhesion of hFOB cells was observed on a PS film with roughness of ~11 nm. When this film was additionally treated by oxygen plasma to provide a hydrophilic surface with a contact angle less than 10°, the proliferation of bone-forming cell was further enhanced. Thus, the plasma-based independent modification of PS film into an optimum nanotexture for human osteoblast cells could be appplied to materials used in bone tissue engineering. Copyright © 2012 Elsevier B.V. All rights reserved.

Annexin A6 contributes to the invasiveness of breast carcinoma cells by influencing the organization and localization of functional focal adhesions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakwe, Amos M., E-mail: asakwe@mmc.edu; Koumangoye, Rainelli; Guillory, Bobby

2011-04-01

The interaction of annexin A6 (AnxA6) with membrane phospholipids and either specific extracellular matrix (ECM) components or F-actin suggests that it may influence cellular processes associated with rapid plasma membrane reorganization such as cell adhesion and motility. Here, we examined the putative roles of AnxA6 in adhesion-related cellular processes that contribute to breast cancer progression. We show that breast cancer cells secrete annexins via the exosomal pathway and that the secreted annexins are predominantly cell surface-associated. Depletion of AnxA6 in the invasive BT-549 breast cancer cells is accompanied by enhanced anchorage-independent cell growth but cell-cell cohesion, cell adhesion/spreading onto collagenmore » type IV or fetuin-A, cell motility and invasiveness were strongly inhibited. To explain the loss in adhesion/motility, we show that vinculin-based focal adhesions in the AnxA6-depleted BT-549 cells are elongated and randomly distributed. These focal contacts are also functionally defective because the activation of focal adhesion kinase and the phosphoinositide-3 kinase/Akt pathway were strongly inhibited while the MAP kinase pathway remained constitutively active. Compared with normal human breast tissues, reduced AnxA6 expression in breast carcinoma tissues correlates with enhanced cell proliferation. Together this suggests that reduced AnxA6 expression contributes to breast cancer progression by promoting the loss of functional cell-cell and/or cell-ECM contacts and anchorage-independent cell proliferation.« less

In vitro Flow Adhesion Assay for Analyzing Shear-resistant Adhesion of Metastatic Cancer Cells to Endothelial Cells.

PubMed

Kang, Shin-Ae; Bajana, Sandra; Tanaka, Takemi

2016-02-20

Hematogenous metastasis is a primary cause of mortality from metastatic cancer. The shear-resistant adhesion of circulating tumor cells to the vascular endothelial cell surface under blood flow is an essential step in cell extravasation and further tissue invasion. This is similar to a process exploited by leukocytes for adhesion to inflamed blood vessels (leukocyte mimicry). The shear resistant adhesion is mediated by high affinity interactions between endothelial adhesion molecules and their counter receptor ligand expressed on circulating cells. Thus, weak interaction results in a rapid detachment of circulating cells from endothelium. Despite the critical role of vascular adhesion of cancer cells in hematogenous metastasis, our knowledge regarding this process has been limited due to the difficulty of mimicking dynamic flow conditions in vitro . In order to gain better insight into the shear-resistant adhesion of cancer cells to the endothelium, we developed a protocol for measuring the shear resistant adhesion of circulating tumor cells to endothelial cells under physiologic flow conditions by adapting a well established flow adhesion assay for inflammatory cells. This technique is useful to evaluate 1) the shear resistant adhesion competency of cancer cells and 2) the endothelial adhesion molecules necessary to support cancer cell adhesion (Kang et al. , 2015).

Different effects of 25-kDa amelogenin on the proliferation, attachment and migration of various periodontal cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xiting; Shu, Rong, E-mail: shurong123@hotmail.com; Liu, Dali

Previous studies have assumed that amelogenin is responsible for the therapeutic effect of the enamel matrix derivative (EMD) in periodontal tissue healing and regeneration. However, it is difficult to confirm this hypothesis because both the EMD and the amelogenins are complex mixtures of multiple proteins. Further adding to the difficulties is the fact that periodontal tissue regeneration involves various types of cells and a sequence of associated cellular events including the attachment, migration and proliferation of various cells. In this study, we investigated the potential effect of a 25-kDa recombinant porcine amelogenin (rPAm) on primarily cultured periodontal ligament fibroblasts (PDLF),more » gingival fibroblasts (GF) and gingival epithelial cells (GEC). The cells were treated with 25-kDa recombinant porcine amelogenin at a concentration of 10 {mu}g/mL. We found that rPAm significantly promoted the proliferation and migration of PDLF, but not their adhesion. Similarly, the proliferation and adhesion of GF were significantly enhanced by treatment with rPAm, while migration was greatly inhibited. Interestingly, this recombinant protein inhibited the growth rate, cell adhesion and migration of GEC. These data suggest that rPAm may play an essential role in periodontal regeneration through the activation of periodontal fibroblasts and inhibition of the cellular behaviors of gingival epithelial cells.« less

EMMPRIN Regulates Cytoskeleton Reorganization and Cell Adhesion in Prostate Cancer

PubMed Central

Zhu, Haining; Zhao, Jun; Zhu, Beibei; Collazo, Joanne; Gal, Jozsef; Shi, Ping; Liu, Li; Ström, Anna-Lena; Lu, Xiaoning; McCann, Richard O.; Toborek, Michal; Kyprianou, Natasha

2011-01-01

Background Proteins on cell surface play important roles during cancer progression and metastasis via their ability to mediate cell-to-cell interactions and navigate the communication between cells and the microenvironment. Methods In this study a targeted proteomic analysis was conducted to identify the differential expression of cell surface proteins in human benign (BPH-1) vs. malignant (LNCaP and PC-3) prostate epithelial cells. We identified EMMPRIN (extracellular matrix metalloproteinase inducer) as a key candidate and shRNA functional approaches were subsequently applied to determine the role of EMMPRIN in prostate cancer cell adhesion, migration, invasion as well as cytoskeleton organization. Results EMMPRIN was found to be highly expressed on the surface of prostate cancer cells compared to BPH-1 cells, consistent with a correlation between elevated EMMPRIN and metastasis found in other tumors. No significant changes in cell proliferation, cell cycle progression or apoptosis were detected in EMMPRIN knockdown cells compared to the scramble controls. Furthermore, EMMPRIN silencing markedly decreased the ability of PC-3 cells to form filopodia, a critical feature of invasive behavior, while it increased expression of cell-cell adhesion and gap junction proteins. Conclusions Our results suggest that EMMPRIN regulates cell adhesion, invasion and cytoskeleton reorganization in prostate cancer cells. This study identifies a new function for EMMPRIN as a contributor to prostate cancer cell-cell communication and cytoskeleton changes towards metastatic spread, and suggests its potential value as a marker of prostate cancer progression to metastasis. PMID:21563192

EMMPRIN regulates cytoskeleton reorganization and cell adhesion in prostate cancer.

PubMed

Zhu, Haining; Zhao, Jun; Zhu, Beibei; Collazo, Joanne; Gal, Jozsef; Shi, Ping; Liu, Li; Ström, Anna-Lena; Lu, Xiaoning; McCann, Richard O; Toborek, Michal; Kyprianou, Natasha

2012-01-01

Proteins on cell surface play important roles during cancer progression and metastasis via their ability to mediate cell-to-cell interactions and navigate the communication between cells and the microenvironment. In this study a targeted proteomic analysis was conducted to identify the differential expression of cell surface proteins in human benign (BPH-1) versus malignant (LNCaP and PC-3) prostate epithelial cells. We identified EMMPRIN (extracellular matrix metalloproteinase inducer) as a key candidate and shRNA functional approaches were subsequently applied to determine the role of EMMPRIN in prostate cancer cell adhesion, migration, invasion as well as cytoskeleton organization. EMMPRIN was found to be highly expressed on the surface of prostate cancer cells compared to BPH-1 cells, consistent with a correlation between elevated EMMPRIN and metastasis found in other tumors. No significant changes in cell proliferation, cell cycle progression, or apoptosis were detected in EMMPRIN knockdown cells compared to the scramble controls. Furthermore, EMMPRIN silencing markedly decreased the ability of PC-3 cells to form filopodia, a critical feature of invasive behavior, while it increased expression of cell-cell adhesion and gap junction proteins. Our results suggest that EMMPRIN regulates cell adhesion, invasion, and cytoskeleton reorganization in prostate cancer cells. This study identifies a new function for EMMPRIN as a contributor to prostate cancer cell-cell communication and cytoskeleton changes towards metastatic spread, and suggests its potential value as a marker of prostate cancer progression to metastasis. Copyright © 2011 Wiley Periodicals, Inc.

Effects of substrate conductivity on cell morphogenesis and proliferation using tailored, atomic layer deposition-grown ZnO thin films

PubMed Central

Choi, Won Jin; Jung, Jongjin; Lee, Sujin; Chung, Yoon Jang; Yang, Cheol-Soo; Lee, Young Kuk; Lee, You-Seop; Park, Joung Kyu; Ko, Hyuk Wan; Lee, Jeong-O

2015-01-01

We demonstrate that ZnO films grown by atomic layer deposition (ALD) can be employed as a substrate to explore the effects of electrical conductivity on cell adhesion, proliferation, and morphogenesis. ZnO substrates with precisely tunable electrical conductivity were fabricated on glass substrates using ALD deposition. The electrical conductivity of the film increased linearly with increasing duration of the ZnO deposition cycle (thickness), whereas other physical characteristics, such as surface energy and roughness, tended to saturate at a certain value. Differences in conductivity dramatically affected the behavior of SF295 glioblastoma cells grown on ZnO films, with high conductivity (thick) ZnO films causing growth arrest and producing SF295 cell morphologies distinct from those cultured on insulating substrates. Based on simple electrostatic calculations, we propose that cells grown on highly conductive substrates may strongly adhere to the substrate without focal-adhesion complex formation, owing to the enhanced electrostatic interaction between cells and the substrate. Thus, the inactivation of focal adhesions leads to cell proliferation arrest. Taken together, the work presented here confirms that substrates with high conductivity disturb the cell-substrate interaction, producing cascading effects on cellular morphogenesis and disrupting proliferation, and suggests that ALD-grown ZnO offers a single-variable method for uniquely tailoring conductivity. PMID:25897486

The microRNA-200 family coordinately regulates cell adhesion and proliferation in hair morphogenesis.

PubMed

Hoefert, Jaimee E; Bjerke, Glen A; Wang, Dongmei; Yi, Rui

2018-06-04

The microRNA (miRNA)-200 (miR-200) family is highly expressed in epithelial cells and frequently lost in metastatic cancer. Despite intensive studies into their roles in cancer, their targets and functions in normal epithelial tissues remain unclear. Importantly, it remains unclear how the two subfamilies of the five-miRNA family, distinguished by a single nucleotide within the seed region, regulate their targets. By directly ligating miRNAs to their targeted mRNA regions, we identify numerous miR-200 targets involved in the regulation of focal adhesion, actin cytoskeleton, cell cycle, and Hippo/Yap signaling. The two subfamilies bind to largely distinct target sites, but many genes are coordinately regulated by both subfamilies. Using inducible and knockout mouse models, we show that the miR-200 family regulates cell adhesion and orientation in the hair germ, contributing to precise cell fate specification and hair morphogenesis. Our findings demonstrate that combinatorial targeting of many genes is critical for miRNA function and provide new insights into miR-200's functions. © 2018 Hoefert et al.

CRISPR-Cas9 Mediated NOX4 Knockout Inhibits Cell Proliferation and Invasion in HeLa Cells.

PubMed

Jafari, Naser; Kim, Hyunju; Park, Rackhyun; Li, Liqing; Jang, Minsu; Morris, Andrew J; Park, Junsoo; Huang, Cai

2017-01-01

Increased expression of NOX4 protein is associated with cancer progression and metastasis but the role of NOX4 in cell proliferation and invasion is not fully understood. We generated NOX4 knockout HeLa cell lines using the CRISPR-Cas9 gene editing system to explore the cellular functions of NOX4. After transfection of CRISPR-Cas9 construct, we performed T7 endonuclease 1 assays and DNA sequencing to generate and identify insertion and deletion of the NOX4 locus. We confirmed the knockout of NOX4 by Western blotting. NOX4 knockout cell lines showed reduced cell proliferation with an increase of sub-G1 cell population and the decrease of S/G2/M population. Moreover, NOX4 deficiency resulted in a dramatic decrease in invadopodium formation and the invasive activity. In addition, NOX4 deficiency also caused a decrease in focal adhesions and cell migration in HeLa cells. These results suggest that NOX4 is required for both efficient proliferation and invasion of HeLa cells.

FRET measurements of cell-traction forces and nano-scale clustering of adhesion ligands varied by substrate stiffness.

PubMed

Kong, Hyun Joon; Polte, Thomas R; Alsberg, Eben; Mooney, David J

2005-03-22

The mechanical properties of cell adhesion substrates regulate cell phenotype, but the mechanism of this relation is currently unclear. It may involve the magnitude of traction force applied by the cell, and/or the ability of the cells to rearrange the cell adhesion molecules presented from the material. In this study, we describe a FRET technique that can be used to evaluate the mechanics of cell-material interactions at the molecular level and simultaneously quantify the cell-based nanoscale rearrangement of the material itself. We found that these events depended on the mechanical rigidity of the adhesion substrate. Furthermore, both the proliferation and differentiation of preosteoblasts (MC3T3-E1) correlated to the magnitude of force that cells generate to cluster the cell adhesion ligands, but not the extent of ligand clustering. Together, these data demonstrate the utility of FRET in analyzing cell-material interactions, and suggest that regulation of phenotype with substrate stiffness is related to alterations in cellular traction forces.

Focal Adhesion-Independent Cell Migration.

PubMed

Paluch, Ewa K; Aspalter, Irene M; Sixt, Michael

2016-10-06

Cell migration is central to a multitude of physiological processes, including embryonic development, immune surveillance, and wound healing, and deregulated migration is key to cancer dissemination. Decades of investigations have uncovered many of the molecular and physical mechanisms underlying cell migration. Together with protrusion extension and cell body retraction, adhesion to the substrate via specific focal adhesion points has long been considered an essential step in cell migration. Although this is true for cells moving on two-dimensional substrates, recent studies have demonstrated that focal adhesions are not required for cells moving in three dimensions, in which confinement is sufficient to maintain a cell in contact with its substrate. Here, we review the investigations that have led to challenging the requirement of specific adhesions for migration, discuss the physical mechanisms proposed for cell body translocation during focal adhesion-independent migration, and highlight the remaining open questions for the future.

SEL1L Regulates Adhesion, Proliferation and Secretion of Insulin by Affecting Integrin Signaling

PubMed Central

Diaferia, Giuseppe R.; Cirulli, Vincenzo; Biunno, Ida

2013-01-01

SEL1L, a component of the endoplasmic reticulum associated degradation (ERAD) pathway, has been reported to regulate the (i) differentiation of the pancreatic endocrine and exocrine tissue during the second transition of mouse embryonic development, (ii) neural stem cell self-renewal and lineage commitment and (iii) cell cycle progression through regulation of genes related to cell-matrix interaction. Here we show that in the pancreas the expression of SEL1L is developmentally regulated, such that it is readily detected in developing islet cells and in nascent acinar clusters adjacent to basement membranes, and becomes progressively restricted to the islets of Langherans in post-natal life. This peculiar expression pattern and the presence of two inverse RGD motifs in the fibronectin type II domain of SEL1L protein indicate a possible interaction with cell adhesion molecules to regulate islets architecture. Co-immunoprecipitation studies revealed SEL1L and ß1-integrin interaction and, down-modulation of SEL1L in pancreatic ß-cells, negatively influences both cell adhesion on selected matrix components and cell proliferation likely due to altered ERK signaling. Furthermore, the absence of SEL1L protein strongly inhibits glucose-stimulated insulin secretion in isolated mouse pancreatic islets unveiling an important role of SEL1L in insulin trafficking. This phenotype can be rescued by the ectopic expression of the ß1-integrin subunit confirming the close interaction of these two proteins in regulating the cross-talk between extracellular matrix and insulin signalling to create a favourable micro-environment for ß-cell development and function. PMID:24324549

Vitisin B, a resveratrol tetramer, inhibits migration through inhibition of PDGF signaling and enhancement of cell adhesiveness in cultured vascular smooth muscle cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ong, Eng-Thaim; Hwang, Tsong-Long; Huang, Yu-Ling

2011-10-15

Vascular smooth muscle cells (VSMCs) play an important role in normal vessel formation and in the development and progression of cardiovascular diseases. Grape plants contain resveratrol monomer and oligomers and drinking of wine made from grape has been linked to 'French Paradox'. In this study we evaluated the effect of vitisin B, a resveratrol tetramer, on VSMC behaviors. Vitisin B inhibited basal and PDGF-induced VSMC migration. Strikingly, it did not inhibit VSMC proliferation but inversely enhanced cell cycle progression and proliferation. Among the tested resveratrol oligomers, vitisin B showed an excellent inhibitory activity and selectivity on PDGF signaling. The anti-migratorymore » effect by vitisin B was due to direct inhibition on PDGF signaling but was independent of interference with PDGF binding to VSMCs. Moreover, the enhanced VSMC adhesiveness to matrix contributed to the anti-migratory effect by vitisin B. Fluorescence microscopy revealed an enhanced reorganization of actin cytoskeleton and redistribution of activated focal adhesion proteins from cytosol to the peripheral edge of the cell membrane. This was confirmed by the observation that enhanced adhesiveness was repressed by the Src inhibitor. Finally, among the effects elicited by vitisin B, only the inhibitory effect toward basal migration was partially through estrogen receptor activation. We have demonstrated here that a resveratrol tetramer exhibited dual but opposite actions on VSMCs, one is to inhibit VSMC migration and the other is to promote VSMC proliferation. The anti-migratory effect was through a potent inhibition on PDGF signaling and novel enhancement on cell adhesion. - Highlights: > Several resveratrol oligomers from grape plants are examined on VSMC behaviors. > Tetraoligomer vitisin B shows excellent inhibitory activity and selectivity. > It exerts dual but opposing actions: anti-migratory and pro-proliferative effects. > The anti-migratory effect results from anti

[Effect of Spatholobus suberctus on adhesion, invasion, migration and metastasis of melanoma cells].

PubMed

Xu, Jian-Ya; Gu, Qin; Xia, Wei-Jun

2010-10-01

To study the effect of Spatholobus suberctus, a kind of Chinese Traditional Medicine which can dissolve the stasis by activating the blood circulation, on invasion, adhesion, migration and metastasis of B16-BL6 metastatic mouse melanoma cells and its mechanism. The proliferation, adhesion, invasion and migration capacity of B16-BL6 metastatic cells was evaluated by MTP assay, adhesion assay and reconstituted basement membrane invasion and migration assay in vitro respectively. Mouse spontaneous motility melanoma model was used to study the effect of Spatholobus suberctus on metastasis in vivo. At the highest innoxious concentration, the extracts of Spatholobus suberctus inhibited the adhesion and invasion capacity of B16-BL6 metastatic cells significantly. In the mouse spontaneous melanoma model, the lung metastatic nodes number and its volume were significantly decreased after continuously treated with the extracts of Spatholobus suberctu. The extracts of Spatholobus suberctu can inhibit the metastasis of of B16-BI6 metastatic mouse melanoma cells and its mechanism may be inhibiting the capability of B16-BL6 cells in adhering to the ECM and invading the basement membrane.

Hybrid cell adhesive material for instant dielectrophoretic cell trapping and long-term cell function assessment.

PubMed

Reyes, Darwin R; Hong, Jennifer S; Elliott, John T; Gaitan, Michael

2011-08-16

Dielectrophoresis (DEP) for cell manipulation has focused, for the most part, on approaches for separation/enrichment of cells of interest. Advancements in cell positioning and immobilization onto substrates for cell culture, either as single cells or as cell aggregates, has benefited from the intensified research efforts in DEP (electrokinetic) manipulation. However, there has yet to be a DEP approach that provides the conditions for cell manipulation while promoting cell function processes such as cell differentiation. Here we present the first demonstration of a system that combines DEP with a hybrid cell adhesive material (hCAM) to allow for cell entrapment and cell function, as demonstrated by cell differentiation into neuronlike cells (NLCs). The hCAM, comprised of polyelectrolytes and fibronectin, was engineered to function as an instantaneous cell adhesive surface after DEP manipulation and to support long-term cell function (cell proliferation, induction, and differentiation). Pluripotent P19 mouse embryonal carcinoma cells flowing within a microchannel were attracted to the DEP electrode surface and remained adhered onto the hCAM coating under a fluid flow field after the DEP forces were removed. Cells remained viable after DEP manipulation for up to 8 d, during which time the P19 cells were induced to differentiate into NLCs. This approach could have further applications in areas such as cell-cell communication, three-dimensional cell aggregates to create cell microenvironments, and cell cocultures.

Serum from plasma rich in growth factors regenerates rabbit corneas by promoting cell proliferation, migration, differentiation, adhesion and limbal stemness.

PubMed

Etxebarria, Jaime; Sanz-Lázaro, Sara; Hernáez-Moya, Raquel; Freire, Vanesa; Durán, Juan A; Morales, María-Celia; Andollo, Noelia

2017-12-01

To evaluate the regenerating potential and the mechanisms through which the autologous serum derived from plasma rich in growth factors (s-PRGF) favours corneal wound healing in vitro and in vivo. We compared the effect of various concentrations of s-PRGF versus fetal bovine serum (FBS) and control treatment in rabbit primary corneal epithelial and stromal cells and wounded rabbit corneas. Cell proliferation was measured using an enzymatic colorimetric assay. In vitro and in vivo wound-healing progression was assessed by image-analysis software. Migration and invasion were evaluated using transfilter assays. Histological structure was analysed in stained sections. Protein expression was evaluated by immunohistochemistry. s-PRGF promoted the robust proliferation of epithelial cultures at any concentration, similar to FBS. Likewise, s-PRGF and FBS produced similar re-epithelialization rates in in vitro wound-healing assays. In vivo, s-PRGF treatment accelerated corneal wound healing in comparison with control treatment. This difference was significant only for 100% s-PRGF treatment in our healthy rabbit model. Histological analysis confirmed normal epithelialization in all cases. Immunohistochemistry showed a higher expression of cytokeratins 3/76 and 15, zonula occludens-1 and alpha-smooth muscle actin proteins as a function of s-PRGF concentration. Notably, keratocyte density in the anterior third of the stroma increased with increase in s-PRGF concentration, suggesting an in vivo chemotactic effect of s-PRGF on keratocytes that was further confirmed in vitro. s-PRGF promotes proliferation and migration and influences limbal stemness, adhesion and fibrosis during corneal healing. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Moderate plasma activated media suppresses proliferation and migration of MDCK epithelial cells

NASA Astrophysics Data System (ADS)

Mohades, Soheila; Laroussi, Mounir; Maruthamuthu, Venkat

2017-05-01

Low-temperature plasma has been shown to have diverse biomedical uses, including its applications in cancer and wound healing. One recent approach in treating mammalian cells with plasma is through the use of plasma activated media (PAM), which is produced by exposing cell culture media to plasma. While the adverse effects of PAM treatment on cancerous epithelial cell lines have been recently studied, much less is known about the interaction of PAM with normal epithelial cells. In this paper, non-cancerous canine kidney MDCK (Madin-Darby Canine Kidney) epithelial cells were treated by PAM and time-lapse microscopy was used to directly monitor their proliferation and random migration upon treatment. While longer durations of PAM treatment led to cell death, we found that moderate levels of PAM treatment inhibited proliferation in these epithelial cells. We also found that PAM treatment reduced random cell migration within epithelial islands. Immunofluorescence staining showed that while there were no major changes in the actin/adhesion apparatus, there was a significant change in the nuclear localization of proliferation marker Ki-67, consistent with our time-lapse results.

Human mesenchymal stem cells target adhesion molecules and receptors involved in T cell extravasation.

PubMed

Benvenuto, Federica; Voci, Adriana; Carminati, Enrico; Gualandi, Francesca; Mancardi, Gianluigi; Uccelli, Antonio; Vergani, Laura

2015-12-10

Systemic delivery of bone marrow-derived mesenchymal stem cells (MSC) seems to be of benefit in the treatment of multiple sclerosis (MS), an autoimmune disease of the central nervous system (CNS) sustained by migration of T cells across the brain blood barrier (BBB) and subsequent induction of inflammatory lesions into CNS. MSC have been found to modulate several effector functions of T cells. In this study, we investigated the effects of MSC on adhesion molecules and receptors on T cell surface that sustain their transendothelial migration. We used different co-culture methods combined with real-time PCR and flow cytometry to evaluate the expression both at the mRNA and at the plasma-membrane level of α4 integrin, β2 integrin, ICAM-1 and CXCR3. In parallel, we assessed if MSC are able to modulate expression of adhesion molecules on the endothelial cells that interact with T cells during their transendothelial migration. Our in vitro analyses revealed that MSC: (i) inhibit proliferation and activation of both peripheral blood mononuclear cells (PBMC) and CD3(+)-selected lymphocytes through the release of soluble factors; (ii) exert suppressive effects on those surface molecules highly expressed by activated lymphocytes and involved in transendothelial migration; (iii) inhibit CXCL10-driven chemotaxis of CD3(+) cells; (iv) down-regulated expression of adhesion molecules on endothelial cells. Taken together, these data demonstrate that the immunosuppressive effect of MSC does not exclusively depends on their anti-proliferative activity on T cells, but also on the impairment of leukocyte migratory potential through the inhibition of the adhesion molecules and receptors that are responsible for T cell trafficking across BBB. This could suggest a new mechanism through which MSC modulate T cell responses.

Immobilisation of hydroxyapatite-collagen on polydopamine grafted stainless steel 316L: Coating adhesion and in vitro cells evaluation.

PubMed

Tapsir, Zafirah; Jamaludin, Farah H; Pingguan-Murphy, Belinda; Saidin, Syafiqah

2018-02-01

The utilisation of hydroxyapatite and collagen as bioactive coating materials could enhance cells attachment, proliferation and osseointegration. However, most methods to form crystal hydroxyapatite coating do not allow the incorporation of polymer/organic compound due to production phase of high sintering temperature. In this study, a polydopamine film was used as an intermediate layer to immobilise hydroxyapatite-collagen without the introduction of high sintering temperature. The surface roughness, coating adhesion, bioactivity and osteoblast attachment on the hydroxyapatite-collagen coating were assessed as these properties remains unknown on the polydopamine grafted film. The coating was developed by grafting stainless steel 316L disks with a polydopamine film. Collagen type I fibres were then immobilised on the grafted film, followed by the biomineralisation of hydroxyapatite. The surface roughness and coating adhesion analyses were later performed by using AFM instrument. An Alamar Blue assay was used to determine the cytotoxicity of the coating, while an alkaline phosphatase activity test was conducted to evaluate the osteogenic differentiation of human fetal osteoblasts on the coating. Finally, the morphology of cells attachment on the coating was visualised under FESEM. The highest RMS roughness and coating adhesion were observed on the hydroxyapatite-collagen coating (hydroxyapatite-coll-dopa). The hydroxyapatite-coll-dopa coating was non-toxic to the osteoblast cells with greater cells proliferation, greater level of alkaline phosphate production and more cells attachment. These results indicate that the immobilisation of hydroxyapatite and collagen using an intermediate polydopamine is identical to enhance coating adhesion, osteoblast cells attachment, proliferation and differentiation, and thus could be implemented as a coating material on orthopaedic and dental implants.

The XTT Cell Proliferation Assay Applied to Cell Layers Embedded in Three-Dimensional Matrix

PubMed Central

Huyck, Lynn; Ampe, Christophe

2012-01-01

Abstract Cell proliferation, a main target in cancer therapy, is influenced by the surrounding three-dimensional (3D) extracellular matrix (ECM). In vitro drug screening is, thus, optimally performed under conditions in which cells are grown (embedded or trapped) in dense 3D matrices, as these most closely mimic the adhesive and mechanical properties of natural ECM. Measuring cell proliferation under these conditions is, however, technically more challenging compared with two-dimensional (2D) culture and other “3D culture conditions,” such as growth on top of a matrix (pseudo-3D) or in spongy scaffolds with large pore sizes. Consequently, such measurements are only slowly applied on a wider scale. To advance this, we report on the equal quality (dynamic range, background, linearity) of measuring the proliferation of cell layers embedded in dense 3D matrices (collagen, Matrigel) compared with cells in 2D culture using the easy (one-step) and in 2D well-validated, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT)-assay. The comparison stresses the differences in proliferation kinetics and drug sensitivity of matrix-embedded cells versus 2D culture. Using the specific cell-layer-embedded 3D matrix setup, quantitative measurements of cell proliferation and cell invasion are shown to be possible in similar assay conditions, and cytostatic, cytotoxic, and anti-invasive drug effects can thus be reliably determined and compared in physiologically relevant settings. This approach in the 3D matrix holds promise for improving early-stage, high-throughput drug screening, targeting either highly invasive or highly proliferative subpopulations of cancers or both. PMID:22574651

Focal adhesion kinase (FAK) perspectives in mechanobiology: implications for cell behaviour.

PubMed

Tomakidi, Pascal; Schulz, Simon; Proksch, Susanne; Weber, Wilfried; Steinberg, Thorsten

2014-09-01

Mechanobiology is a scientific interface discipline emerging from engineering and biology. With regard to tissue-regenerative cell-based strategies, mechanobiological concepts, including biomechanics as a target for cell and human mesenchymal stem cell behaviour, are on the march. Based on the periodontium as a paradigm, this mini-review discusses the key role of focal-adhesion kinase (FAK) in mechanobiology, since it is involved in mediating the transformation of environmental biomechanical signals into cell behavioural responses via mechanotransducing signalling cascades. These processes enable cells to adjust quickly to environmental cues, whereas adjustment itself relies on the specific intramolecular phosphorylation of FAK tyrosine residues and the multiple interactions of FAK with distinct partners. Furthermore, interaction-triggered mechanotransducing pathways govern the dynamics of focal adhesion sites and cell behaviour. Facets of behaviour not only include cell spreading and motility, but also proliferation, differentiation and apoptosis. In translational terms, identified and characterized biomechanical parameters can be incorporated into innovative concepts of cell- and tissue-tailored clinically applied biomaterials controlling cell behaviour as desired.

Overexpression of Activin Receptor-like Kinase 7 in Breast Cancer Cells Is Associated with Decreased Cell Growth and Adhesion.

PubMed

Hu, Tingting; Su, Fengxi; Jiang, Wenguo; Dart, D Alwyn

2017-07-01

To examine the expression and function of activin receptor-like kinase 7 (ALK7) in breast cancer, its association with disease prognosis, and its impact on breast cancer cell function. A cohort of patients with breast cancer were examined for ALK7 expression in association with pathological and clinical aspects. In vitro cell assays of ALK7 were investigated using an expression plasmid. Overall higher levels of ALK7 transcripts were seen in the breast cancer samples vs. normal tissue. However, within the cancer cohort, lower levels of ALK7 transcript were associated with poor prognosis. Patients with lower expression of ALK7 also had shorter survival. Overexpression of ALK7 reduced proliferation and adhesion of breast cancer cells in vitro. We found that overexpressed ALK7 had complex effects on the MCF-7 cell sensitivity to chemotherapy drugs. Decreased expression of ALK7 in breast cancer is correlated with poor prognosis. ALK7 is a negative regulator of adhesion and proliferation of breast cancer cells. This suggests that ALK7 is a potential tumor suppressor in breast cancer. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Splicing factors PTBP1 and PTBP2 promote proliferation and migration of glioma cell lines

PubMed Central

Cheung, Hannah C.; Hai, Tao; Zhu, Wen; Baggerly, Keith A.; Tsavachidis, Spiridon; Krahe, Ralf

2009-01-01

Polypyrimidine tract-binding protein 1 (PTBP1) is a multi-functional RNA-binding protein that is aberrantly overexpressed in glioma. PTBP1 and its brain-specific homologue polypyrimidine tract-binding protein 2 (PTBP2) regulate neural precursor cell differentiation. However, the overlapping and non-overlapping target transcripts involved in this process are still unclear. To determine why PTBP1 and not PTBP2 would promote glial cell-derived tumours, both PTBP1 and PTBP2 were knocked down in the human glioma cell lines U251 and LN229 to determine the role of these proteins in cell proliferation, migration, and adhesion. Surprisingly, removal of both PTBP1 and PTBP2 slowed cell proliferation, with the double knockdown having no additive effects. Decreased expression of both proteins individually and in combination inhibited cell migration and increased adhesion of cells to fibronectin and vitronectin. A global survey of differential exon expression was performed following PTBP1 knockdown in U251 cells using the Affymetrix Exon Array to identify PTBP1-specific splicing targets that enhance gliomagenesis. In the PTBP1 knockdown, previously determined targets were unaltered in their splicing patterns. A single gene, RTN4 (Nogo) had significantly enhanced inclusion of exon 3 when PTBP1 was removed. Overexpression of the splice isoform containing exon 3 decreased cell proliferation to a similar degree as the removal of PTBP1. These results provide the first evidence that RNA-binding proteins affect the invasive and rapid growth characteristics of glioma cell lines. Its actions on proliferation appear to be mediated, in part, through alternative splicing of RTN4. PMID:19506066

Combinatorial growth of oxide nanoscaffolds and its influence in osteoblast cell adhesion

NASA Astrophysics Data System (ADS)

Acevedo-Morantes, Claudia Y.; Irizarry-Ortiz, Roberto A.; Caceres-Valencia, Pablo G.; Singh, Surinder P.; Ramirez-Vick, Jaime E.

2012-05-01

We report a novel method for high-throughput investigations on cell-material interactions based on metal oxide nanoscaffolds. These scaffolds possess a continuous gradient of various titanium alloys allowing the compositional and morphological variation that could substantially improve the formation of an osseointegrative interface with bone. The model nanoscaffold has been fabricated on commercially pure titanium (cp-Ti) substrate with a compositional gradients of tin (Sn), chromium (Cr), and niobium (Nb) deposited using a combinatorial approach followed by annealing to create native oxide surface. As an invitro test system, the human fetal osteoblastic cell line (hFOB 1.19) has been used. Cell-adhesion of hFOB 1.19 cells and the suitability of these alloys have been evaluated for cell-morphology, cell-number, and protein adsorption. Although, cell-morphology was not affected by surface composition, cell-proliferation rates varied significantly with surface metal oxide composition; with the Sn- and Nb-rich regions showing the highest proliferation rate and the Cr-rich regions presenting the lowest. The results suggest that Sn and Nb rich regions on surface seems to promote hFOB 1.19 cell proliferation and may therefore be considered as implant material candidates that deserve further analysis.

Effects of nerve cells and adhesion molecules on nerve conduit for peripheral nerve regeneration

PubMed Central

Fiorellini, Joseph P.

2017-01-01

Background For peripheral nerve regeneration, recent attentions have been paid to the nerve conduits made by tissue-engineering technique. Three major elements of tissue-engineering are cells, molecules, and scaffolds. Methods In this study, the attachments of nerve cells, including Schwann cells, on the nerve conduit and the effects of both growth factor and adhesion molecule on these attachments were investigated. Results The attachment of rapidly-proliferating cells, C6 cells and HS683 cells, on nerve conduit was better than that of slowly-proliferating cells, PC12 cells and Schwann cells, however, the treatment of nerve growth factor improved the attachment of slowly-proliferating cells. In addition, the attachment of Schwann cells on nerve conduit coated with fibronectin was as good as that of Schwann cells treated with glial cell line-derived neurotrophic factor (GDNF). Conclusions Growth factor changes nerve cell morphology and affects cell cycle time. And nerve growth factor or fibronectin treatment is indispensable for Schwann cell to be used for implantation in artificial nerve conduits. PMID:29090249

Adhesive interactions of human multiple myeloma cell lines with different extracellular matrix molecules.

PubMed

Kibler, C; Schermutzki, F; Waller, H D; Timpl, R; Müller, C A; Klein, G

1998-06-01

Multiple myeloma represents a human B cell malignancy which is characterized by a predominant localization of the malignant cell clone within the bone marrow. With the exception of the terminal stage of the disease the myeloma tumor cells do not circulate in the peripheral blood. The bone marrow microenvironment is believed to play an important role in homing, proliferation and terminal differentiation of myeloma cells. Here we have studied the expression of several extracellular matrix (ECM) molecules in the bone marrow of multiple myeloma patients and analyzed their adhesive capacities with four different human myeloma-derived cell lines. All ECM molecules analyzed (tenascin, laminin, fibronectin, collagen types I, III, V and VI) could be detected in bone marrow cryostat sections of multiple myeloma patients. Adhesion assays showed that only laminin, the microfibrillar collagen type VI and fibronectin were strong adhesive components for the myeloma cell lines U266, IM-9, OPM-2 and NCI-H929. Tenascin and collagen type I were only weak adhesive substrates for these myeloma cells. Adhesion to laminin and fibronectin was beta 1-integrin-mediated since addition of anti-beta 1-integrin antibodies could inhibit the binding of the four different cell types to both matrix molecules. In contrast, integrins do not seem to be involved in binding of the myeloma cells to collagen type VI. Instead, inhibition of binding by heparin suggested that membrane-bound heparan sulfate proteoglycans are responsible ligands for binding to collagen type VI. Adhesion assays with several B-cell lines resembling earlier differentiation stages revealed only weak interactions with tenascin and no interactions with collagen type VI, laminin or fibronectin. In summary, the interactions of human myeloma cells with the extracellular matrix may explain the specific retention of the plasma cells within the bone marrow.

Biofunctionalized 3-D Carbon Nano-Network Platform for Enhanced Fibroblast Cell Adhesion

NASA Astrophysics Data System (ADS)

Chowdhury, A. K. M. Rezaul Haque; Tavangar, Amirhossein; Tan, Bo; Venkatakrishnan, Krishnan

2017-03-01

Carbon nanomaterials have been investigated for various biomedical applications. In most cases, however, these nanomaterials must be functionalized biologically or chemically due to their biological inertness or possible cytotoxicity. Here, we report the development of a new carbon nanomaterial with a bioactive phase that significantly promotes cell adhesion. We synthesize the bioactive phase by introducing self-assembled nanotopography and altered nano-chemistry to graphite substrates using ultrafast laser. To the best of our knowledge, this is the first time that such a cytophilic bio-carbon is developed in a single step without requiring subsequent biological/chemical treatments. By controlling the nano-network concentration and chemistry, we develop platforms with different degrees of cell cytophilicity. We study quantitatively and qualitatively the cell response to nano-network platforms with NIH-3T3 fibroblasts. The findings from the in vitro study indicate that the platforms possess excellent biocompatibility and promote cell adhesion considerably. The study of the cell morphology shows a healthy attachment of cells with a well-spread shape, overextended actin filaments, and morphological symmetry, which is indicative of a high cellular interaction with the nano-network. The developed nanomaterial possesses great biocompatibility and considerably stimulates cell adhesion and subsequent cell proliferation, thus offering a promising path toward engineering various biomedical devices.

The extracellular adherence protein (Eap) of Staphylococcus aureus acts as a proliferation and migration repressing factor that alters the cell morphology of keratinocytes.

PubMed

Eisenbeis, Janina; Peisker, Henrik; Backes, Christian S; Bur, Stephanie; Hölters, Sebastian; Thewes, Nicolas; Greiner, Markus; Junker, Christian; Schwarz, Eva C; Hoth, Markus; Junker, Kerstin; Preissner, Klaus T; Jacobs, Karin; Herrmann, Mathias; Bischoff, Markus

2017-02-01

Staphyloccocus aureus is a major human pathogen and a common cause for superficial and deep seated wound infections. The pathogen is equipped with a large arsenal of virulence factors, which facilitate attachment to various eukaryotic cell structures and modulate the host immune response. One of these factors is the extracellular adherence protein Eap, a member of the "secretable expanded repertoire adhesive molecules" (SERAM) protein family that possesses adhesive and immune modulatory properties. The secreted protein was previously shown to impair wound healing by interfering with host defense and neovascularization. However, its impact on keratinocyte proliferation and migration, two major steps in the re-epithelialization process of wounds, is not known. Here, we report that Eap affects the proliferation and migration capacities of keratinocytes by altering their morphology and adhesive properties. In particular, treatment of non-confluent HaCaT cell cultures with Eap resulted in cell morphology changes as well as a significant reduction in cell proliferation and migration. Eap-treated HaCaT cells changed their appearance from an oblong via a trapezoid to an astral-like shape, accompanied by decreases in cell volume and cell stiffness, and exhibited significantly increased cell adhesion. Eap had a similar influence on endothelial and cancer cells, indicative for a general effect of Eap on eukaryotic cell morphology and functions. Specifically, Eap was found to interfere with growth factor-stimulated activation of the mitogen-activated protein kinase (MAPK) pathway that is known to be responsible for cell shape modulation, induction of proliferation and migration of epithelial cells. Western blot analyses revealed that Eap blocked the phosphorylation of extracellular signal-regulated kinase 1 and 2 (Erk1/2) in keratinocyte growth factor (KGF)-stimulated HaCaT cells. Together, these data add another antagonistic mechanism of Eap in wound healing, whereby the

Cell Adhesions: Actin-Based Modules that Mediate Cell-Extracellular Matrix and Cell-Cell Interactions

PubMed Central

Bachir, Alexia; Horwitz, Alan Rick; Nelson, W. James; Bianchini, Julie M.

2018-01-01

Cell adhesions link cells to the extracellular matrix (ECM) and to each other, and depend on interactions with the actin cytoskeleton. Both cell-ECM and cell-cell adhesion sites contain discrete, yet overlapping functional modules. These modules establish physical association with the actin cytoskeleton, locally modulate actin organization and dynamics, and trigger intracellular signaling pathways. Interplay between these modules generates distinct actin architectures that underlie different stages, types, and functions of cell-ECM and cell-cell adhesions. Actomyosin contractility is required to generate mature, stable adhesions, as well as sense and translate the mechanical properties of the cellular environment to changes in cell organization and behavior. In this chapter we discuss the organization and function of different adhesion modules and how they interact with the actin cytoskeleton. We highlight the molecular mechanisms of mechanotransduction in adhesions, and how adhesion molecules mediate crosstalk between cell-ECM and cell-cell adhesion sites. PMID:28679638

Increased Cell Proliferation and Gene Expression of Genes Related to Bone Remodeling, Cell Adhesion and Collagen Metabolism in the Periodontal Ligament of Unopposed Molars in Growing Rats

PubMed Central

Dorotheou, Domna; Farsadaki, Vassiliki; Bochaton-Piallat, Marie-Luce; Giannopoulou, Catherine; Halazonetis, Thanos D.; Kiliaridis, Stavros

2017-01-01

Tooth eruption, the process by which teeth emerge from within the alveolar bone into the oral cavity, is poorly understood. The post-emergent phase of tooth eruption continues throughout life, in particular, if teeth are not opposed by antagonists. The aim of the present study was to better understand the molecular processes underlying post-emergent tooth eruption. Toward this goal, we removed the crowns of the maxillary molars on one side of the mouth of 14 young rats and examined gene expression patterns in the periodontal ligaments (PDLs) of the ipsilateral and contralateral mandibular molars, 3 and 15 days later. Nine untreated rats served as controls. Expression of six genes, Adamts18, Ostn, P4ha3, Panx3, Pth1r, and Tnmd, was upregulated in unopposed molars relative to molars with antagonists. These genes function in osteoblast differentiation and proliferation, cell adhesion and collagen metabolism. Proliferation of PDL cells also increased following loss of the antagonist teeth. Interestingly, mutations in PTH1R have been linked to defects in the post-emergent phase of tooth eruption in humans. We conclude that post-emergent eruption of unopposed teeth is associated with gene expression patterns conducive to alveolar bone formation and PDL remodeling. PMID:28239357

[Expression of cell adhesion molecules in acute leukemia cell].

PubMed

Ju, Xiaoping; Peng, Min; Xu, Xiaoping; Lu, Shuqing; Li, Yao; Ying, Kang; Xie, Yi; Mao, Yumin; Xia, Fang

2002-11-01

To investigate the role of cell adhesion molecule in the development and extramedullary infiltration (EI) of acute leukemia. The expressions of neural cell adhesion molecule (NCAM) gene, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1) genes in 25 acute leukemia patients bone marrow cells were detected by microarray and reverse transcriptase-polymerase chain reaction (RT-PCR). The expressions of NCAM, ICAM-1 and VCAM-1 gene were significantly higher in acute leukemia cells and leukemia cells with EI than in normal tissues and leukemia cells without EI, respectively, both by cDNA microarray and by RT-PCR. The cDNA microarray is a powerful technique in analysis of acute leukemia cells associated genes. High expressions of cell adhesion molecule genes might be correlated with leukemia pathogenesis and infiltration of acute leukemia cell.

Engineered electrospun poly(caprolactone)/polycaprolactone-g-hydroxyapatite nano-fibrous scaffold promotes human fibroblasts adhesion and proliferation.

PubMed

Keivani, F; Shokrollahi, P; Zandi, M; Irani, S; F Shokrolahi; Khorasani, S C

2016-11-01

Polycaprolactone (PCL)/hydroxyapatite nano-composites are among the best candidates for tissue engineering. However, interactions between nHAp and PCL are difficult to control leading to inhomogeneous dispersion of the bio-ceramic particles. Grafting of polymer chains at high density/chain length while promotes the phase compatibility may result in reduced HAp exposed surface area and therefore, bioactivity is compromised. This issue is addressed here by grafting PCL chains onto HAp nano-particles through ring opening polymerization of ε-caprolactone (PCL-g-HAp). FTIR and TGA analysis showed that PCL (6.9wt%), was successfully grafted on the HAp. PCL/PCL-g-HAp nano-fibrous scaffold showed up to 10 and 33% enhancement in tensile strength and modulus, respectively, compared to those of PCL/HAp. The effects of HAp on the in vitro HAp formation were investigated for both the PCL/HAp and PCL/PCL-g-HAp scaffolds. Precipitation of HAp on the nano-composite scaffolds observed after 15days incubation in simulated body fluid (SBF), as confirmed by scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). Human fibroblasts were seeded on PCL, PCL/HAp and PCL/PCL-g-HAp scaffolds. According to MTT assay, the highest cell proliferation was recorded for PCL/PCL-g-HAp nano-composite, at all time intervals (1-21days, P<0.001). Fluorescent microscopy (of DAPI stained samples) and electron microscopy images showed that all nano-fibrous scaffolds (PCL, PCL/HAp, and PCL/PCL-g-HAp), were non-toxic against cells, while more cell adhesion, and the most uniform cell distribution observed on the PCL/PCL-g-HAp. Overall, grafting of relatively short chains of PCL on the surface of HAp nano-particles stimulates fibroblasts adhesion and proliferation on the PCL/PCL-g-HAp nano-composite. Copyright © 2016 Elsevier B.V. All rights reserved.

Simple surface engineering of polydimethylsiloxane with polydopamine for stabilized mesenchymal stem cell adhesion and multipotency

PubMed Central

Chuah, Yon Jin; Koh, Yi Ting; Lim, Kaiyang; Menon, Nishanth V.; Wu, Yingnan; Kang, Yuejun

2015-01-01

Polydimethylsiloxane (PDMS) has been extensively exploited to study stem cell physiology in the field of mechanobiology and microfluidic chips due to their transparency, low cost and ease of fabrication. However, its intrinsic high hydrophobicity renders a surface incompatible for prolonged cell adhesion and proliferation. Plasma-treated or protein-coated PDMS shows some improvement but these strategies are often short-lived with either cell aggregates formation or cell sheet dissociation. Recently, chemical functionalization of PDMS surfaces has proved to be able to stabilize long-term culture but the chemicals and procedures involved are not user- and eco-friendly. Herein, we aim to tailor greener and biocompatible PDMS surfaces by developing a one-step bio-inspired polydopamine coating strategy to stabilize long-term bone marrow stromal cell culture on PDMS substrates. Characterization of the polydopamine-coated PDMS surfaces has revealed changes in surface wettability and presence of hydroxyl and secondary amines as compared to uncoated surfaces. These changes in PDMS surface profile contribute to the stability in BMSCs adhesion, proliferation and multipotency. This simple methodology can significantly enhance the biocompatibility of PDMS-based microfluidic devices for long-term cell analysis or mechanobiological studies. PMID:26647719

Influence of electrospun scaffolds prepared from distinct polymers on proliferation and viability of endothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matveeva, V. G., E-mail: matveeva-vg@mail.ru; Antonova, L. V., E-mail: antonova.la@mail.ru; Velikanova, E. A.

We compared electrospun nonwoven scaffolds from polylactic acid (PLA), polycaprolactone (PCL), and polyhydroxybutyrate/valerate (PHBV)/polycaprolactone (PHBV/PCL). The surface of PHBV/PCL and PCL scaffolds was highly porous and consisted of randomly distributed fibers, whilst the surface of PLA scaffolds consisted of thin straight fibers, which located more sparsely, forming large pores. Culture of EA.hy 926 endothelial cells on these scaffolds during 7 days and further fluorescent microscopy demonstrated that the surface of PHBV/PCL scaffolds was most favorable for efficient adhesion, proliferation, and viability of endothelial cells. The lowest proliferation rate and cell viability were detected on PLA scaffolds. Therefore, PHBV/PCL electrospun nonwovenmore » scaffolds demonstrated the best results regarding endothelial cell proliferation and viability as compared to PCL and PLA scaffolds.« less

Emergence of collective propulsion through cell-cell adhesion.

PubMed

Matsushita, Katsuyoshi

2018-04-01

The mechanisms driving the collective movement of cells remain poorly understood. To contribute toward resolving this mystery, a model was formulated to theoretically explore the possible functions of polarized cell-cell adhesion in collective cell migration. The model consists of an amoeba cell with polarized cell-cell adhesion, which is controlled by positive feedback with cell motion. This model cell has no persistent propulsion and therefore exhibits a simple random walk when in isolation. However, at high density, these cells acquire collective propulsion and form ordered movement. This result suggests that cell-cell adhesion has a potential function, which induces collective propulsion with persistence.

Emergence of collective propulsion through cell-cell adhesion

NASA Astrophysics Data System (ADS)

Matsushita, Katsuyoshi

2018-04-01

The mechanisms driving the collective movement of cells remain poorly understood. To contribute toward resolving this mystery, a model was formulated to theoretically explore the possible functions of polarized cell-cell adhesion in collective cell migration. The model consists of an amoeba cell with polarized cell-cell adhesion, which is controlled by positive feedback with cell motion. This model cell has no persistent propulsion and therefore exhibits a simple random walk when in isolation. However, at high density, these cells acquire collective propulsion and form ordered movement. This result suggests that cell-cell adhesion has a potential function, which induces collective propulsion with persistence.

Effect of Pirfenidone on Vascular Proliferation, Inflammation and Fibrosis in an Abdominal Adhesion Rat Model.

PubMed

Hasdemir, Pinar Solmaz; Ozkut, Mahmud; Guvenal, Tevfik; Uner, Melis Aylin; Calik, Esat; Koltan, Semra Oruc; Koyuncu, Faik Mumtaz; Ozbilgin, Kemal

2017-02-01

To study the efficacy of pirfenidone for prevention of postoperative adhesion formation in an adhesion rat model. Eighteen female Wistar rats were subjected to right-sided parietal peritoneum and right uterine horn adhesion model. Rats were randomized into three groups: group 1 (control) (closure of midline abdominal incision without any agent administration), group 2 (closure of incision after intraperitoneal administration of pirfenidone), and group 3 (closure of incision and only oral administration of pirfenidone for 14 days). Relaparotomy was performed 14 days after the first surgery. Effect of pirfenidone on adhesion formation was assessed on light microscopy by scoring vascular proliferation, inflammation, fibrosis, and collagen formation in the scarred tissue. Effect of pirfenidone on inflammation was assessed by measurement of transforming growth factor-β and interleukin-17 levels in scarred tissue. The degree of vascular proliferation (1.32 ± 0.39 versus 2.34 ± 0.46, p < 0.001), inflammation (1.60 ± 0.70 versus 2.60 ± 0.52, p < 0.01), and fibrosis (1.50 ± 0.53 versus 2.40 ± 0.52, p < 0.01) were less prominent in group 2 compared to group 1, respectively. Only vascular proliferation was found to be less prominent in group 3 compared to group 1 (1.60 ± 0.42 versus 2.34 ± 0.46, p < 0.01). Intraperitoneal and oral administration of pirfenidone reduced tissue levels of inflammatory markers (TGF-β and IL-17) in parietal and visceral peritoneum compared to control group. Intraperitoneal administration of pirfenidone compared to oral administration was more effective in reducing tissue levels of inflammatory markers. Pirfenidone is an effective agent on the prevention of postoperative vascular proliferation, inflammation and fibrosis in scarred tissue particularly with intraperitoneal administration.

Cell adhesion molecule-1 (CADM1) expressed on adult T-cell leukemia/lymphoma cells is not involved in the interaction with macrophages.

PubMed

Komohara, Yoshihiro; Ma, Chaoya; Yano, Hiromu; Pan, Cheng; Horlad, Hasita; Saito, Yoichi; Ohnishi, Koji; Fujiwara, Yukio; Okuno, Yutaka; Nosaka, Kisato; Shimosaki, Shunsuke; Morishita, Kazuhiro; Matsuoka, Masao; Wakayama, Tomohiko; Takeya, Motohiro

2017-07-05

Cell adhesion molecule 1 (CADM1) is a cell adhesion molecule that is expressed in brain, liver, lung, testis, and some kinds of cancer cells including adult T-cell leukemia/lymphoma (ATLL). Recent studies have indicated the involvement of CADM1 in cell-cell contact between cytotoxic T-lymphocytes and virus infected cells. We previously reported that cell-cell interaction between lymphoma cells and macrophages induces lymphoma cell proliferation. In the present study, we investigated whether CADM1 is associated with cell-cell interaction between several human lymphoma cell lines and macrophages.CADM1 expression was observed in the ATLL cell lines, ATN-1, ATL-T, and ATL-35T, and in the B cell lymphoma cell lines, TL-1, DAUDI, and SLVL, using western blotting. Significant cell-cell interaction between macrophages and ATN-1, ATL-T, ATL-35T and MT-2, DAUDI, and SLVL cells, as assessed by induction of cell proliferation, was observed. Immunohistochemical analysis of human biopsy samples indicated CADM1 expression in 10 of 14 ATLL cases; however, no case of follicular lymphoma or diffuse large B-cell lymphoma was positive for CADM1. Finally, the interaction of macrophages with cells of the CADM1-negative ED ATLL cell line and CADM1-transfected ED cells was tested. However, significant cell-cell interaction between macrophage and CADM1-transfected ED cells was not observed. We conclude that CADM1 was not associated with cell-cell interaction between lymphoma cells and macrophages, although CADM1 may be a useful marker of ATLL for diagnostic procedures.

E-Selectin Mediates Stem Cell Adhesion and Formation of Blood Vessels in a Murine Model of Infantile Hemangioma

PubMed Central

Smadja, David M.; Mulliken, John B.; Bischoff, Joyce

2013-01-01

Hemangioma stem cells (HemSCs) are multipotent cells isolated from infantile hemangioma (IH), which form hemangioma-like lesions when injected subcutaneously into immune-deficient mice. In this murine model, HemSCs are the primary target of corticosteroid, a mainstay therapy for problematic IH. The relationship between HemSCs and endothelial cells that reside in IH is not clearly understood. Adhesive interactions might be critical for the preferential accumulation of HemSCs and/or endothelial cells in the tumor. Therefore, we studied the interactions between HemSCs and endothelial cells (HemECs) isolated from IH surgical specimens. We found that HemECs isolated from proliferating phase IH, but not involuting phase, constitutively express E-selectin, a cell adhesion molecule not present in quiescent endothelial cells. E-selectin was further increased when HemECs were exposed to vascular endothelial growth factor–A or tumor necrosis factor–α. In vitro, HemSC migration and adhesion was enhanced by recombinant E-selectin but not P-selectin; both processes were neutralized by E-selectin–blocking antibodies. E-selectin–positive HemECs also stimulated migration and adhesion of HemSCs. In vivo, neutralizing antibodies to E-selectin strongly inhibited formation of blood vessels when HemSCs and HemECs were co-implanted in Matrigel. These data suggest that endothelial E-selectin could be a major ligand for HemSCs and thereby promote cellular interactions and vasculogenesis in IH. We propose that constitutively expressed E-selectin on endothelial cells in the proliferating phase is one mediator of the stem cell tropism in IH. PMID:23041613

Angiotensin Converting Enzyme Regulates Cell Proliferation and Migration

PubMed Central

Carvalho, Clarissa Coelho; Florentino, Rodrigo Machado; França, Andressa; Matias, Eveline; Guimarães, Paola Bianchi; Batista, Carolina; Freire, Valder; Carmona, Adriana Karaoglanovic; Pesquero, João Bosco; de Paula, Ana Maria; Foureaux, Giselle; Leite, Maria de Fatima

2016-01-01

Background The angiotensin-I converting enzyme (ACE) plays a central role in the renin-angiotensin system, acting by converting the hormone angiotensin-I to the active peptide angiotensin-II (Ang-II). More recently, ACE was shown to act as a receptor for Ang-II, and its expression level was demonstrated to be higher in melanoma cells compared to their normal counterparts. However, the function that ACE plays as an Ang-II receptor in melanoma cells has not been defined yet. Aim Therefore, our aim was to examine the role of ACE in tumor cell proliferation and migration. Results We found that upon binding to ACE, Ang-II internalizes with a faster onset compared to the binding of Ang-II to its classical AT1 receptor. We also found that the complex Ang-II/ACE translocates to the nucleus, through a clathrin-mediated process, triggering a transient nuclear Ca2+ signal. In silico studies revealed a possible interaction site between ACE and phospholipase C (PLC), and experimental results in CHO cells, demonstrated that the β3 isoform of PLC is the one involved in the Ca2+ signals induced by Ang-II/ACE interaction. Further studies in melanoma cells (TM-5) showed that Ang-II induced cell proliferation through ACE activation, an event that could be inhibited either by ACE inhibitor (Lisinopril) or by the silencing of ACE. In addition, we found that stimulation of ACE by Ang-II caused the melanoma cells to migrate, at least in part due to decreased vinculin expression, a focal adhesion structural protein. Conclusion ACE activation regulates melanoma cell proliferation and migration. PMID:27992423

Soluble adhesion molecules in human cancers: sources and fates.

PubMed

van Kilsdonk, Jeroen W J; van Kempen, Léon C L T; van Muijen, Goos N P; Ruiter, Dirk J; Swart, Guido W M

2010-06-01

Adhesion molecules endow tumor cells with the necessary cell-cell contacts and cell-matrix interactions. As such, adhesion molecules are involved in cell signalling, proliferation and tumor growth. Rearrangements in the adhesion repertoire allow tumor cells to migrate, invade and form metastases. Besides these membrane-bound adhesion molecules several soluble adhesion molecules are detected in the supernatant of tumor cell lines and patient body fluids. Truncated soluble adhesion molecules can be generated by several conventional mechanisms, including alternative splicing of mRNA transcripts, chromosomal translocation, and extracellular proteolytic ectodomain shedding. Secretion of vesicles (ectosomes and exosomes) is an alternative mechanism mediating the release of full-length adhesion molecules. Soluble adhesion molecules function as modulators of cell adhesion, induce proteolytic activity and facilitate cell signalling. Additionally, adhesion molecules present on secreted vesicles might be involved in the vesicle-target cell interaction. Based on currently available data, released soluble adhesion molecules contribute to cancer progression and therefore should not be regarded as unrelated and non-functional side products of tumor progression. 2010 Elsevier GmbH. All rights reserved.

In silico characterization of cell-cell interactions using a cellular automata model of cell culture.

PubMed

Kihara, Takanori; Kashitani, Kosuke; Miyake, Jun

2017-07-14

Cell proliferation is a key characteristic of eukaryotic cells. During cell proliferation, cells interact with each other. In this study, we developed a cellular automata model to estimate cell-cell interactions using experimentally obtained images of cultured cells. We used four types of cells; HeLa cells, human osteosarcoma (HOS) cells, rat mesenchymal stem cells (MSCs), and rat smooth muscle A7r5 cells. These cells were cultured and stained daily. The obtained cell images were binarized and clipped into squares containing about 10 4 cells. These cells showed characteristic cell proliferation patterns. The growth curves of these cells were generated from the cell proliferation images and we determined the doubling time of these cells from the growth curves. We developed a simple cellular automata system with an easily accessible graphical user interface. This system has five variable parameters, namely, initial cell number, doubling time, motility, cell-cell adhesion, and cell-cell contact inhibition (of proliferation). Within these parameters, we obtained initial cell numbers and doubling times experimentally. We set the motility at a constant value because the effect of the parameter for our simulation was restricted. Therefore, we simulated cell proliferation behavior with cell-cell adhesion and cell-cell contact inhibition as variables. By comparing growth curves and proliferation cell images, we succeeded in determining the cell-cell interaction properties of each cell. Simulated HeLa and HOS cells exhibited low cell-cell adhesion and weak cell-cell contact inhibition. Simulated MSCs exhibited high cell-cell adhesion and positive cell-cell contact inhibition. Simulated A7r5 cells exhibited low cell-cell adhesion and strong cell-cell contact inhibition. These simulated results correlated with the experimental growth curves and proliferation images. Our simulation approach is an easy method for evaluating the cell-cell interaction properties of cells.

L1CAM stimulates glioma cell motility and proliferation through the fibroblast growth factor receptor.

PubMed

Mohanan, Vishnu; Temburni, Murali K; Kappes, John C; Galileo, Deni S

2013-04-01

The L1CAM cell adhesion/recognition molecule (L1, CD171) and fibroblast growth factor receptor (FGFR) both are expressed by human high-grade glioma cells, but their potential actions in controlling cell behavior have not been linked. L1 actions in cancer cells have been attributed mainly to integrin receptors, and we demonstrated previously that L1-stimulated glioma cell migration correlates with integrin expression, increased focal adhesion kinase activation and focal complex turnover. Our analyses of datasets revealed FGFR is overexpressed in glioma regardless of grade, while ADAM10 metalloprotease expression increases with glioma grade. Here, we used dominant-negative and short hairpin RNA approaches to inhibit the activation of FGFR1 and expression of L1, respectively. An L1 peptide that inhibits L1-FGFR interaction and PD173074, a chemical inhibitor of FGFR1 activity, also were used to elucidate the involvement of L1-FGFR interactions on glioma cell behavior. Time-lapse cell motility studies and flow cytometry cell cycle analyses showed that L1 operates to increase glioma cell motility and proliferation through FGFR activation. Shutdown of both L1 expression and FGFR activity in glioma cells resulted in a complete termination of cell migration in vitro. These studies show for the first time that soluble L1 ectodomain (L1LE) acts on glioma cells through FGFRs, and that FGFRs are used by glioma cells for increasing motility as well as proliferation in response to activation by L1LE ligand. Thus, effective treatment of high-grade glioma may require simultaneous targeting of L1, FGFRs, and integrin receptors, which would reduce glioma cell motility as well as proliferation.

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

PubMed

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.

RP1 Is a Phosphorylation Target of CK2 and Is Involved in Cell Adhesion

PubMed Central

Göttig, Stephan; Henschler, Reinhard; Markuly, Norbert; Kleber, Sascha; Faust, Michael; Mischo, Axel; Bauer, Stefan; Zweifel, Martin; Knuth, Alexander; Renner, Christoph; Wadle, Andreas

2013-01-01

RP1 (synonym: MAPRE2, EB2) is a member of the microtubule binding EB1 protein family, which interacts with APC, a key regulatory molecule in the Wnt signalling pathway. While the other EB1 proteins are well characterized the cellular function and regulation of RP1 remain speculative to date. However, recently RP1 has been implicated in pancreatic cancerogenesis. CK2 is a pleiotropic kinase involved in adhesion, proliferation and anti-apoptosis. Overexpression of protein kinase CK2 is a hallmark of many cancers and supports the malignant phenotype of tumor cells. In this study we investigate the interaction of protein kinase CK2 with RP1 and demonstrate that CK2 phosphorylates RP1 at Ser236 in vitro. Stable RP1 expression in cell lines leads to a significant cleavage and down-regulation of N-cadherin and impaired adhesion. Cells expressing a Phospho-mimicking point mutant RP1-ASP236 show a marked decrease of adhesion to endothelial cells under shear stress. Inversely, we found that the cells under shear stress downregulate endogenous RP1, most likely to improve cellular adhesion. Accordingly, when RP1 expression is suppressed by shRNA, cells lacking RP1 display significantly increased cell adherence to surfaces. In summary, RP1 phosphorylation at Ser236 by CK2 seems to play a significant role in cell adhesion and might initiate new insights in the CK2 and EB1 family protein association. PMID:23844040

RP1 is a phosphorylation target of CK2 and is involved in cell adhesion.

PubMed

Stenner, Frank; Liewen, Heike; Göttig, Stephan; Henschler, Reinhard; Markuly, Norbert; Kleber, Sascha; Faust, Michael; Mischo, Axel; Bauer, Stefan; Zweifel, Martin; Knuth, Alexander; Renner, Christoph; Wadle, Andreas

2013-01-01

RP1 (synonym: MAPRE2, EB2) is a member of the microtubule binding EB1 protein family, which interacts with APC, a key regulatory molecule in the Wnt signalling pathway. While the other EB1 proteins are well characterized the cellular function and regulation of RP1 remain speculative to date. However, recently RP1 has been implicated in pancreatic cancerogenesis. CK2 is a pleiotropic kinase involved in adhesion, proliferation and anti-apoptosis. Overexpression of protein kinase CK2 is a hallmark of many cancers and supports the malignant phenotype of tumor cells. In this study we investigate the interaction of protein kinase CK2 with RP1 and demonstrate that CK2 phosphorylates RP1 at Ser(236) in vitro. Stable RP1 expression in cell lines leads to a significant cleavage and down-regulation of N-cadherin and impaired adhesion. Cells expressing a Phospho-mimicking point mutant RP1-ASP(236) show a marked decrease of adhesion to endothelial cells under shear stress. Inversely, we found that the cells under shear stress downregulate endogenous RP1, most likely to improve cellular adhesion. Accordingly, when RP1 expression is suppressed by shRNA, cells lacking RP1 display significantly increased cell adherence to surfaces. In summary, RP1 phosphorylation at Ser(236) by CK2 seems to play a significant role in cell adhesion and might initiate new insights in the CK2 and EB1 family protein association.

The molecular mechanism of mediation of adsorbed serum proteins to endothelial cells adhesion and growth on biomaterials.

PubMed

Yang, Dayun; Lü, Xiaoying; Hong, Ying; Xi, Tingfei; Zhang, Deyuan

2013-07-01

To explore molecular mechanism of mediation of adsorbed proteins to cell adhesion and growth on biomaterials, this study examined endothelial cell adhesion, morphology and viability on bare and titanium nitride (TiN) coated nickel titanium (NiTi) alloys and chitosan film firstly, and then identified the type and amount of serum proteins adsorbed on the three surfaces by proteomic technology. Subsequently, the mediation role of the identified proteins to cell adhesion and growth was investigated with bioinformatics analyses, and further confirmed by a series of cellular and molecular biological experiments. Results showed that the type and amount of adsorbed serum proteins associated with cell adhesion and growth was obviously higher on the alloys than on the chitosan film, and these proteins mediated endothelial cell adhesion and growth on the alloys via four ways. First, proteins such as adiponectin in the adsorbed protein layer bound with cell surface receptors to generate signal transduction, which activated cell surface integrins through increasing intracellular calcium level. Another way, thrombospondin 1 in the adsorbed protein layer promoted TGF-β signaling pathway activation and enhanced integrins expression. The third, RGD sequence containing proteins such as fibronectin 1, vitronectin and thrombospondin 1 in the adsorbed protein layer bound with activated integrins to activate focal adhesion pathway, increased focal adhesion formation and actin cytoskeleton organization and mediated cell adhesion and spreading. In addition, the activated focal adhesion pathway promoted the expression of cell growth related genes and resulted in cell proliferation. The fourth route, coagulation factor II (F2) and fibronectin 1 in the adsorbed protein layer bound with cell surface F2 receptor and integrin, activated regulation of actin cytoskeleton pathway and regulated actin cytoskeleton organization. Copyright © 2013 Elsevier Ltd. All rights reserved.

E-selectin mediates stem cell adhesion and formation of blood vessels in a murine model of infantile hemangioma.

PubMed

Smadja, David M; Mulliken, John B; Bischoff, Joyce

2012-12-01

Hemangioma stem cells (HemSCs) are multipotent cells isolated from infantile hemangioma (IH), which form hemangioma-like lesions when injected subcutaneously into immune-deficient mice. In this murine model, HemSCs are the primary target of corticosteroid, a mainstay therapy for problematic IH. The relationship between HemSCs and endothelial cells that reside in IH is not clearly understood. Adhesive interactions might be critical for the preferential accumulation of HemSCs and/or endothelial cells in the tumor. Therefore, we studied the interactions between HemSCs and endothelial cells (HemECs) isolated from IH surgical specimens. We found that HemECs isolated from proliferating phase IH, but not involuting phase, constitutively express E-selectin, a cell adhesion molecule not present in quiescent endothelial cells. E-selectin was further increased when HemECs were exposed to vascular endothelial growth factor-A or tumor necrosis factor-α. In vitro, HemSC migration and adhesion was enhanced by recombinant E-selectin but not P-selectin; both processes were neutralized by E-selectin-blocking antibodies. E-selectin-positive HemECs also stimulated migration and adhesion of HemSCs. In vivo, neutralizing antibodies to E-selectin strongly inhibited formation of blood vessels when HemSCs and HemECs were co-implanted in Matrigel. These data suggest that endothelial E-selectin could be a major ligand for HemSCs and thereby promote cellular interactions and vasculogenesis in IH. We propose that constitutively expressed E-selectin on endothelial cells in the proliferating phase is one mediator of the stem cell tropism in IH. Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Roles of cell-cell adhesion-dependent tyrosine phosphorylation of Gab-1.

PubMed

Shinohara, M; Kodama, A; Matozaki, T; Fukuhara, A; Tachibana, K; Nakanishi, H; Takai, Y

2001-06-01

Gab-1 is a multiple docking protein that is tyrosine phosphorylated by receptor tyrosine kinases such as c-Met, hepatocyte growth factor/scatter factor receptor, and epidermal growth factor receptor. We have now demonstrated that cell-cell adhesion also induces marked tyrosine phosphorylation of Gab-1 and that disruption of cell-cell adhesion results in its dephosphorylation. An anti-E-cadherin antibody decreased cell-cell adhesion-dependent tyrosine phosphorylation of Gab-1, whereas the expression of E-cadherin specifically induced tyrosine phosphorylation of Gab-1. A relatively selective inhibitor of Src family kinases reduced cell-cell adhesion-dependent tyrosine phosphorylation of Gab-1, whereas expression of a dominant-negative mutant of Csk increased it. Disruption of cell-cell adhesion, which reduced tyrosine phosphorylation of Gab-1, also reduced the activation of mitogen-activated protein kinase and Akt in response to cell-cell adhesion. These results indicate that E-cadherin-mediated cell-cell adhesion induces tyrosine phosphorylation by a Src family kinase of Gab-1, thereby regulating the activation of Ras/MAP kinase and phosphatidylinositol 3-kinase/Akt cascades.

Microfluidic Fabrication of Cell Adhesive Chitosan Microtubes

PubMed Central

Oh, Jonghyun; Kim, Keekyoung; Won, Sung Wook; Cha, Chaenyung; Gaharwar, Akhilesh; Selimović, Šeila; Bae, Hojae; Lee, Kwang Ho; Lee, Dong Hwan; Lee, Sang-Hoon; Khademhosseini, Ali

2013-01-01

Chitosan has been used as a scaffolding material in tissue engineering due to its mechanical properties and biocompatibility. With increased appreciation of the effect of micro- and nanoscale environments on cellular behavior, there is increased emphasis on generating microfabricated chitosan structures. Here we employed a microfluidic coaxial flow-focusing system to generate cell adhesive chitosan microtubes of controlled sizes by modifying the flow rates of a chitosan pre-polymer solution and phosphate buffered saline (PBS). The microtubes were extruded from a glass capillary with a 300 μm inner diameter. After ionic crosslinking with sodium tripolyphosphate (TPP), fabricated microtubes had inner and outer diameter ranges of 70-150 μm and 120-185 μm. Computational simulation validated the controlled size of microtubes and cell attachment. To enhance cell adhesiveness on the microtubes, we mixed gelatin with the chitosan pre-polymer solution and adjusted the pH values of the chitosan pre-polymer solution with gelatin and TPP. During the fabrication of microtubes, fibroblasts suspended in core PBS flow adhered to the inner surface of chitosan-gelatin microtubes. To achieve physiological pH values, we adjusted pH values of chiotsan pre-polymer solution and TPP. In particular, we were able to improve cell viability to 92% with pH values of 5.8 and 7.4 for chitosan and TPP solution respectively. Cell culturing for three days showed that the addition of the gelatin enhanced cell spreading and proliferation inside the chitosan-gelatin microtubes. The microfluidic fabrication method for ionically crosslinked chitosan microtubes at physiological pH can be compatible with a variety of cells and used as a versatile platform for microengineered tissue engineering. PMID:23355068

Effect of zirconium nitride physical vapor deposition coating on preosteoblast cell adhesion and proliferation onto titanium screws.

PubMed

Rizzi, Manuela; Gatti, Giorgio; Migliario, Mario; Marchese, Leonardo; Rocchetti, Vincenzo; Renò, Filippo

2014-11-01

Titanium has long been used to produce dental implants. Problems related to its manufacturing, casting, welding, and ceramic application for dental prostheses still limit its use, which highlights the need for technologic improvements. The aim of this in vitro study was to evaluate the biologic performance of titanium dental implants coated with zirconium nitride in a murine preosteoblast cellular model. The purpose of this study was to evaluate the chemical and morphologic characteristics of titanium implants coated with zirconium nitride by means of physical vapor deposition. Chemical and morphologic characterizations were performed by scanning electron microscopy and energy dispersive x-ray spectroscopy, and the bioactivity of the implants was evaluated by cell-counting experiments. Scanning electron microscopy and energy dispersive x-ray spectroscopy analysis found that physical vapor deposition was effective in covering titanium surfaces with zirconium nitride. Murine MC-3T3 preosteoblasts were seeded onto titanium-coated and zirconium nitride-coated screws to evaluate their adhesion and proliferation. These experiments found a significantly higher number of cells adhering and spreading onto zirconium nitride-coated surfaces (P<.05) after 24 hours; after 7 days, both titanium and zirconium nitride surfaces were completely covered with MC-3T3 cells. Analysis of these data indicates that the proposed zirconium nitride coating of titanium implants could make the surface of the titanium more bioactive than uncoated titanium surfaces. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

6-Methylsulfinylhexyl isothiocyanate modulates endothelial cell function and suppresses leukocyte adhesion.

PubMed

Okamoto, Takayuki; Akita, Nobuyuki; Nagai, Masashi; Hayashi, Tatsuya; Suzuki, Koji

2014-01-01

6-Methylsulfinylhexyl isothiocyanate (6-MSITC) is an active compound in wasabi (Wasabia japonica Matsum.), which is one of the most popular spices in Japan. 6-MSITC suppresses lipopolysaccharide-induced macrophage activation, arachidonic- or adenosine diphosphate-induced platelet activation, and tumor cell proliferation. These data indicate that 6-MSITC has several biological activities involving anti-inflammatory, anti-coagulant, and anti-apoptosis properties. Endothelial cells (ECs) maintain vascular homeostasis and play crucial roles in crosstalk between blood coagulation and vascular inflammation. In this study, we determined the anti-coagulant and anti-inflammatory effects of 6-MSITC on human umbilical vein endothelial cells (HUVECs). 6-MSITC slightly reduced tissue factor expression, but did not alter von Willebrand factor release in activated HUVECs. 6-MSITC modulated the generation of activated protein C, which is essential for negative regulation of blood coagulation, on normal ECs. In addition, 6-MSITC reduced tumor necrosis factor-α (TNF-α)-induced interleukin-6 and monocyte chemoattractant protein-1 expression. 6-MSITC markedly attenuated TNF-α-induced adhesion of human monoblast U937 cells to HUVECs and reduced vascular cell adhesion molecule-1 and E-selectin mRNA expression in activated ECs. These results showed that 6-MSITC modulates EC function and suppresses cell adhesion. This study provides new insight into the mechanism of the anti-inflammatory effect of 6-MSITC, suggesting that 6-MSITC has therapeutic potential as a treatment for vasculitis and vascular inflammation.

Microfabricated Nanotopological Surfaces for Study of Adhesion-dependent Cell mechanosensitivity**

PubMed Central

Chen, Weiqiang; Sun, Yubing

2014-01-01

Cells display high sensitivity and exhibit diverse responses to the intrinsic nanotopography of the extracellular matrix through their nanoscale cellular sensing machinery. Here, we reported a simple microfabrication method for precise control and spatial patterning of the local nanoroughness on glass surfaces using photolithography and reactive ion etching (RIE). Using RIE-generated nanorough glass surfaces, we demonstrated that local nanoroughness could provide a potent biophysical signal to regulate a diverse array of NIH/3T3 fibroblast behaviors, including cell morphology, adhesion, proliferation and migration. We further showed that cellular responses to nanotopography might be regulated by cell adhesion signaling and actin cytoskeleton remodeling. To further investigate the role of cytoskeleton contractility in nanoroughness sensing, we applied the RIE method to generate nanoroughness on the tops of an array of elastomeric poly-dimethylsiloxane (PDMS) microposts. We utilized the PDMS microposts as force sensors and demonstrated that nanoroughness could indeed regulate the cytoskeleton contractility of NIH/3T3 fibroblasts. Our results suggested that a feedback regulation and mechano-chemical integration mechanism involving adhesion signaling, actin cytoskeleton, and intracellular mechanosensory components might play an important role in regulating mechanosensitive behaviors of NIH/3T3 fibroblasts. The capability to control and further predict cellular responses to nanoroughness might suggest novel methods for developing biomaterials mimicking nanotopographic structures in vivo and suitable local cellular microenvironments for functional tissue engineering. PMID:22887768

Cell adhesion on nanotopography

NASA Astrophysics Data System (ADS)

Tsai, Irene; Kimura, Masahiro; Stockton, Rebecca; Jacobson, Bruce; Russell, Thomas

2003-03-01

Cell adhesion, a key element in understanding the cell-biomaterial interactions, underpins proper cell growth, function and survival. Understanding the parameters influencing cell adhesion is critical for applications in biosensors, implants and bioreactors. A gradient surface is used to study the effect of the surface topography on cell adhesion. A gradient surface is generated by block copolymer and homopolymer blends. The two homopolymers will phase separate on the micron scale and gradually decrease to nano-scale by the microphase separation of the diblock. Gradient surfaces offer a unique opportunity to probe lateral variations in the topography and interactions. Using thin films of mixtures of diblock copolymers of PS-b-MMA with PS and PMMA homopolymers, where the concentration of the PS-b-MMA varies across the surface, a gradient in the size scale of the morphology, from the nanoscopic to microscopic, was produced. By UV exposure, the variation in morphology translated into a variation in topography. The extent of cell spreading and cytoskeleton formation was investigated and marked dependence on the length scale of the surface topography was found.

Polymerisation of fibrin αC-domains promotes endothelial cell migration and proliferation.

PubMed

Yakovlev, S; Mikhailenko, I; Tsurupa, G; Belkin, A M; Medved, L

2014-12-01

Upon conversion of fibrinogen into fibrin, fibrinogen αC-domains containing the RGD recognition motif form ordered αC polymers. Our previous study revealed that polymerisation of these domains promotes integrin-dependent adhesion and spreading of endothelial cells, as well as integrin-mediated activation of the FAK and ERK1/2 signalling pathways. The major goal of this study was to test the impact of αC-domain polymerisation on endothelial cell migration and proliferation during wound healing, and to clarify the mechanism underlying superior activity of αC polymers toward endothelial cells. In an in vitro wound healing assay, confluent endothelial cell monolayers on tissue culture plates coated with the αC monomer or αC polymers were wounded by scratching and wound closure was monitored by time-lapse videomicroscopy. Although the plates were coated with equal amounts of αC species, as confirmed by ELISA, wound closure by the cells occurred much faster on αC polymers, indicating that αC-domain polymerisation promotes cell migration and proliferation. In agreement, endothelial cell proliferation was also more efficient on αC polymers, as revealed by cell proliferation assay. Wound closure on both types of substrates was equally inhibited by the integrin-blocking GRGDSP peptide and a specific antagonist of the ERK1/2 signalling pathway. In contrast, blocking the FAK signaling pathway by a specific antagonist decreased wound closure only on αC polymers. These results indicate that polymerisation of the αC-domains enhances integrin-dependent endothelial cell migration and proliferation mainly through the FAK signalling pathway. Furthermore, clustering of integrin-binding RGD motifs in αC polymers is the major mechanism triggering these events.

FAK Regulates Intestinal Epithelial Cell Survival and Proliferation during Mucosal Wound Healing

PubMed Central

Tilghman, Robert W.; Casanova, James E.; Bouton, Amy H.

2011-01-01

Background Following damage to the intestinal epithelium, restoration of epithelial barrier integrity is triggered by a robust proliferative response. In other tissues, focal adhesion kinase (FAK) regulates many of the cellular processes that are critical for epithelial homeostasis and restitution, including cell migration, proliferation and survival. However, few studies to date have determined how FAK contributes to mucosal wound healing in vivo. Methodology and Principal Findings To examine the role of FAK in intestinal epithelial homeostasis and during injury, we generated intestinal epithelium (IE)-specific conditional FAK knockout mice. Colitis was induced with dextran-sulfate-sodium (DSS) and intestinal tissues were analyzed by immunohistochemistry and immunoblotting. While intestinal development occurred normally in mice lacking FAK, FAK-deficient animals were profoundly susceptible to colitis. The loss of epithelial FAK resulted in elevated p53 expression and an increased sensitivity to apoptosis, coincident with a failure to upregulate epithelial cell proliferation. FAK has been reported to function as a mechanosensor, inducing cyclin D1 expression and promoting cell cycle progression under conditions in which tissue/matrix stiffness is increased. Collagen deposition, a hallmark of inflammatory injury resulting in increased tissue rigidity, was observed in control and FAK knockout mice during colitis. Despite this fibrotic response, the colonic epithelium in FAK-deficient mice exhibited significantly reduced cyclin D1 expression, suggesting that proliferation is uncoupled from fibrosis in the absence of FAK. In support of this hypothesis, proliferation of Caco-2 cells increased proportionally with matrix stiffness in vitro only under conditions of normal FAK expression; FAK depleted cells exhibited reduced proliferation concomitant with attenuated cyclin D1 expression. Conclusions In the colon, FAK functions as a regulator of epithelial cell survival and

Slug/SNAI2 regulates cell proliferation and invasiveness of metastatic prostate cancer cell lines.

PubMed

Emadi Baygi, Modjtaba; Soheili, Zahra-Soheila; Essmann, Frank; Deezagi, Abdolkhaleg; Engers, Rainer; Goering, Wolfgang; Schulz, Wolfgang A

2010-08-01

Many metastatic cancers recapitulate the epithelial-to-mesenchymal transition (EMT) resulting in enhanced cell motility and invasiveness. The EMT is regulated by several transcription factors, including the zinc finger protein SNAI2, also named Slug, which appears to exert additional functions during development and cancer progression. We have studied the function of SNAI2 in prostate cancer cells. Quantitative RT-PCR analysis showed strong SNAI2 expression particularly in the PC-3 and PC3-16 prostate carcinoma cell lines. Knockdown of SNAI2 by specific siRNA induced changes in EMT markers and inhibited invasion of both cell lines into a matrigel matrix. SNAI2 siRNA-treated cells did not tolerate detachment from the culture plates, likely at least in part due to downregulation of integrin alpha6beta4. SNAI2 knockdown disturbed the microtubular and actin cytoskeletons, especially severely in PC-3 cells, resulting in grossly enlarged, flattened, and sometimes multinuclear cells. Knockdown also decreased cell proliferation, with a prominent G0/G1 arrest in PC3-16. Together, our data imply that SNAI2 exerts strong effects on the cytoskeleton and adhesion of those prostate cancer cells that express it and is necessary for their proliferation and invasiveness.

Physical and biological properties of a novel anti-adhesion material made of thermally cross-linked gelatin film: Investigation of the usefulness as anti-adhesion material.

PubMed

Horii, Tsunehito; Tsujimoto, Hiroyuki; Miyamoto, Hiroe; Yamanaka, Koki; Tanaka, Shota; Torii, Hiroko; Ozamoto, Yuki; Takamori, Hideki; Nakamachi, Eiji; Ikada, Yoshito; Hagiwara, Akeo

2018-02-01

To create more useful, effective and safer anti-adhesion materials, we developed a thermally cross-linked gelatin film. In this study, we examined the physical properties of the film such as the physical strength and the adhesiveness to reveal the handling properties and biological properties, such as the anti-adhesion effect, the influence on cell proliferation, and the cytotoxicity to reveal the anti-adhesion mechanism, especially in comparison with the conventional hyaluronic acid and carboxymethylcellulose film (the conventional film). A tensile test under dry and wet conditions and shearing stress test showed that the gelatin film has significant higher maximum tensile stress and fracture strain than the conventional film. In the study using a rat model of cecum adhesion, the anti-adhesion effect of the gelatin film was significantly superior to that of the conventional film. In the cell proliferation test, the number of fibroblast cells on the gelatin film increased at each time point, while no cell proliferation was observed on the conventional film. Furthermore, in the cytotoxicity test using a colony assay and Live/Dead assay, the extract of the gelatin film had no cytotoxicity, while the extract of the conventional film had cytotoxicity considerably. These results suggest that the gelatin film provides better handling than the conventional film, due to better physical strength and ductility of the film. In addition, the gelatin film has a significantly greater anti-adhesion effect than the conventional film without any cytotoxicity. Therefore, the gelatin film is quite favorable as an anti-adhesion material. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 689-696, 2018. © 2017 Wiley Periodicals, Inc.

Human Gastric Mucins Differently Regulate Helicobacter pylori Proliferation, Gene Expression and Interactions with Host Cells

PubMed Central

Skoog, Emma C.; Sjöling, Åsa; Navabi, Nazanin; Holgersson, Jan; Lundin, Samuel B.; Lindén, Sara K.

2012-01-01

Helicobacter pylori colonizes the mucus niche of the gastric mucosa and is a risk factor for gastritis, ulcers and cancer. The main components of the mucus layer are heavily glycosylated mucins, to which H. pylori can adhere. Mucin glycosylation differs between individuals and changes during disease. Here we have examined the H. pylori response to purified mucins from a range of tumor and normal human gastric tissue samples. Our results demonstrate that mucins from different individuals differ in how they modulate both proliferation and gene expression of H. pylori. The mucin effect on proliferation varied significantly between samples, and ranged from stimulatory to inhibitory, depending on the type of mucins and the ability of the mucins to bind to H. pylori. Tumor-derived mucins and mucins from the surface mucosa had potential to stimulate proliferation, while gland-derived mucins tended to inhibit proliferation and mucins from healthy uninfected individuals showed little effect. Artificial glycoconjugates containing H. pylori ligands also modulated H. pylori proliferation, albeit to a lesser degree than human mucins. Expression of genes important for the pathogenicity of H. pylori (babA, sabA, cagA, flaA and ureA) appeared co-regulated in response to mucins. The addition of mucins to co-cultures of H. pylori and gastric epithelial cells protected the viability of the cells and modulated the cytokine production in a manner that differed between individuals, was partially dependent of adhesion of H. pylori to the gastric cells, but also revealed that other mucin factors in addition to adhesion are important for H. pylori-induced host signaling. The combined data reveal host-specific effects on proliferation, gene expression and virulence of H. pylori due to the gastric mucin environment, demonstrating a dynamic interplay between the bacterium and its host. PMID:22563496

Effect of testosterone incorporation on cell proliferation and differentiation for polymer-bioceramic composites.

PubMed

da Costa, Kelen Jorge Rodrigues; Passos, Joel J; Gomes, Alinne D M; Sinisterra, Rubén D; Lanza, Célia R M; Cortés, Maria Esperanza

2012-11-01

In the current study, we characterized the polycaprolactone (PCL), poly(lactic acid-co-glycolic acid) (PLGA), and biphasic calcium phosphate (BCP) composites coated with testosterone propionate (T) using Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (XRD). Osteoblastic cells were seeded with PCL/BCP, PCL/BCP/T, PLGA/PCL/BCP and PLGA/PCL/BCP/T scaffolds, and cell viability, proliferation, differentiation and adhesion were analyzed. The results of physic-chemical experiments showed no displacements or suppression of bands in the FTIR spectra of scaffolds. The XRD patterns of the scaffolds showed an amorphous profile. The osteoblastic cells viability and proliferation increased in the presence of composites with testosterone over 72 h, and were significantly greater when PLGA/PCL/BCP/T scaffold was tested against PCL/BCP/T. Furthermore alkaline phosphatase production was significantly greater in the same group. In conclusion, the PLGA/PCL/BCP scaffold with testosterone could be a promising option for bone tissue applications due to its biocompatibility and its stimulatory effect on cell proliferation.

Mitigated reactive oxygen species generation leads to an improvement of cell proliferation on poly[glycidyl methacrylate-co-poly(ethylene glycol) methacrylate] functionalized polydimethylsiloxane surfaces.

PubMed

Yu, Ling; Shi, ZhuanZhuan; Gao, LiXia; Li, ChangMing

2015-09-01

In vitro cell-based analysis is strongly affected by material's surface chemical properties. The cell spreading, migration, and proliferation on a substrate surface are initiated and controlled by successful adhesion, particularly for anchor-dependent cells. Unfortunately, polydimethylsiloxane (PDMS), one of the most used polymeric materials for construction of microfluidic and miniaturized biomedical analytic devices, is not a cell-friendly surface because of its inherent hydrophobic property. Herein, a poly[glycidyl methacrylate-co-poly(ethylene glycol) methacrylate] (poly(GMA-co-pEGMA)) polymer brush was synthesized on a PDMS surface through a surface-initiated atom-transfer radical polymerization method. Contact angle and Fourier transform infrared characterization show that the poly (GMA-co-pEGMA) polymer brush functionalization can increase wettability of PDMS and introduce epoxy, hydroxyl, and ether groups into PDMS surface. In vitro cell growth assay demonstrates that cell adhesion and proliferation on poly(GMA-co-pEGMA) polymer brush-functionalized PDMS (poly(GMA-co-pEGMA)@PDMS) are better than on pristine PDMS. Additionally, immobilization of collagen type I (CI) and fibronectin (FN) on poly(GMA-co-pEGMA)@PDMS is better than direct coating of CI and FN on pristine PDMS to promote cell adhesion. Furthermore, increased intracellular reactive oxygen species and cell mitochondrial membrane depolarization, two indicators of cell oxidative stress, are observed from cells growing on pristine PDMS, but not from those on poly(GMA-co-pEGMA)@PDMS. Collectively, we demonstrate that poly(GMA-co-pEGMA) functionalization can enhance cell adhesion and proliferation on PDMS, and thus can be potentially used for microfluidic cell assay devices for cellular physiology study or drug screening. © 2015 Wiley Periodicals, Inc.

Scalable topographies to support proliferation and Oct4 expression by human induced pluripotent stem cells.

PubMed

Reimer, Andreas; Vasilevich, Aliaksei; Hulshof, Frits; Viswanathan, Priyalakshmi; van Blitterswijk, Clemens A; de Boer, Jan; Watt, Fiona M

2016-01-13

It is well established that topographical features modulate cell behaviour, including cell morphology, proliferation and differentiation. To define the effects of topography on human induced pluripotent stem cells (iPSC), we plated cells on a topographical library containing over 1000 different features in medium lacking animal products (xeno-free). Using high content imaging, we determined the effect of each topography on cell proliferation and expression of the pluripotency marker Oct4 24 h after seeding. Features that maintained Oct4 expression also supported proliferation and cell-cell adhesion at 24 h, and by 4 days colonies of Oct4-positive, Sox2-positive cells had formed. Computational analysis revealed that small feature size was the most important determinant of pluripotency, followed by high wave number and high feature density. Using this information we correctly predicted whether any given topography within our library would support the pluripotent state at 24 h. This approach not only facilitates the design of substrates for optimal human iPSC expansion, but also, potentially, identification of topographies with other desirable characteristics, such as promoting differentiation.

N-cadherin adhesive interactions modulate matrix mechanosensing and fate commitment of mesenchymal stem cells

NASA Astrophysics Data System (ADS)

Cosgrove, Brian D.; Mui, Keeley L.; Driscoll, Tristan P.; Caliari, Steven R.; Mehta, Kush D.; Assoian, Richard K.; Burdick, Jason A.; Mauck, Robert L.

2016-12-01

During mesenchymal development, the microenvironment gradually transitions from one that is rich in cell-cell interactions to one that is dominated by cell-ECM (extracellular matrix) interactions. Because these cues cannot readily be decoupled in vitro or in vivo, how they converge to regulate mesenchymal stem cell (MSC) mechanosensing is not fully understood. Here, we show that a hyaluronic acid hydrogel system enables, across a physiological range of ECM stiffness, the independent co-presentation of the HAVDI adhesive motif from the EC1 domain of N-cadherin and the RGD adhesive motif from fibronectin. Decoupled presentation of these cues revealed that HAVDI ligation (at constant RGD ligation) reduced the contractile state and thereby nuclear YAP/TAZ localization in MSCs, resulting in altered interpretation of ECM stiffness and subsequent changes in downstream cell proliferation and differentiation. Our findings reveal that, in an evolving developmental context, HAVDI/N-cadherin interactions can alter stem cell perception of the stiffening extracellular microenvironment.

Adhesion to the extracellular matrix is positively regulated by retinoic acid in HepG2 cells.

PubMed

Massimi, Mara; Devirgiliis, Laura Conti

2007-02-01

In this work, we aimed to investigate the possible modulation of cell-matrix interactions by retinoic acid (RA), in view of the well-known role of the extracellular matrix (ECM) and integrins in hepatocyte differentiation and proliferation. For this purpose, we analysed the adhesion ability of HepG2 cells on different substrates in the presence and absence of RA evaluating both the expression and cellular localisation of major proteins involved in focal contacts, using Western blot and confocal microscopy. A positive and substrate-dependent effect of RA on cell-matrix adhesion was observed after long-term culture. The increased adhesiveness in the treated cells was accompanied by an enhanced expression of beta1 and alpha3 integrin subunits, together with a redistribution of beta1 receptors clustered at the basal surface. In contrast, the levels of focal adhesion kinase (FAK), paxillin and alpha-actinin were unchanged, as was the phosphorylation state of FAK. Nonetheless, a stronger association between beta1 integrin and intracytoplasmatic proteins of focal contacts was observed in coimmunoprecipitation experiments after RA treatment, suggesting improved connection with the actin cytoskeleton. These results are consistent with previously described antiproliferative and differentiative effects of RA on transformed hepatocytes, and confirm the hypothesis of a direct influence of RA on specific adhesion molecules.

Microfluidic cell trap array for controlled positioning of single cells on adhesive micropatterns.

PubMed

Lin, Laiyi; Chu, Yeh-Shiu; Thiery, Jean Paul; Lim, Chwee Teck; Rodriguez, Isabel

2013-02-21

Adhesive micropattern arrays permit the continuous monitoring and systematic study of the behavior of spatially confined cells of well-defined shape and size in ordered configurations. This technique has contributed to defining mechanisms that control cell polarity and cell functions, including proliferation, apoptosis, differentiation and migration in two-dimensional cell culture systems. These micropattern studies often involve isolating a single cell on one adhesive protein micropattern using random seeding methods. Random seeding has been successful for isolated and, to a lesser degree, paired patterns, where two patterns are placed in close proximity. Using this method, we found that the probability of obtaining one cell per pattern decreases significantly as the number of micropatterns in a cluster increases, from 16% for paired micropatterns to 0.3% for clusters of 6 micropatterns. This work presents a simple yet effective platform based on a microfludic sieve-like trap array to exert precise control over the positioning of single cells on micropatterns. We observed a 4-fold improvement over random seeding in the efficiency of placing a pair of single cells on paired micropattern and a 40-fold improvement for 6-pattern clusters. The controlled nature of this platform can also allow the juxtaposition of two different cell populations through a simple modification in the trap arrangement. With excellent control of the identity, number and position of neighbouring cells, this cell-positioning platform provides a unique opportunity for the extension of two-dimensional micropattern studies beyond paired micropatterns to organizations containing many cells or different cell types.

Effects on in vitro and in vivo angiogenesis induced by small peptides carrying adhesion sequences.

PubMed

Conconi, Maria Teresa; Ghezzo, Francesca; Dettin, Monica; Urbani, Luca; Grandi, Claudio; Guidolin, Diego; Nico, Beatrice; Di Bello, Carlo; Ribatti, Domenico; Parnigotto, Pier Paolo

2010-07-01

It is well known that tumor growth is strictly dependent on neo-vessel formation inside the tumor mass and that cell adhesion is required to allow EC proliferation and migration inside the tumor. In this work, we have evaluated the in vitro and in vivo effects on angiogenesis of some peptides, originally designed to promote cell adhesion on biomaterials, containing RGD motif mediating cell adhesion via integrin receptors [RGD, GRGDSPK, and (GRGDSP)(4)K] or the heparin-binding sequence of human vitronectin that interacts with HSPGs [HVP(351-359)]. Cell adhesion, proliferation, migration, and capillary-like tube formation in Matrigel were determined on HUVECs, whereas the effects on in vivo angiogenesis were evaluated using the CAM assay. (GRGDSP)(4)K linear sequence inhibited cell adhesion, decreased cell proliferation, migration and morphogenesis in Matrigel, and induced anti-angiogenic responses on CAM at higher degree than that determined after incubation with RGD or GRGDSPK. Moreover, it counteracted both in vitro and in vivo the pro-angiogenic effects induced by the Fibroblast growth factor (FGF-2). On the other hand, HVP was not able to affect cell adhesion and appeared less effective than (GRGDSP)(4)K. Our data indicate that the activity of RGD-containing peptides is related to their adhesive properties, and their effects are modulated by the number of cell adhesion motifs and the aminoacidic residues next to these sequences. The anti-angiogenic properties of (GRGDSP)(4)K seem to depend on its interaction with integrins, whereas the effects of HVP may be partially due to an impairment of HSPGs/FGF-2.

Cell adhesion heterogeneity reinforces tumour cell dissemination: novel insights from a mathematical model.

PubMed

Reher, David; Klink, Barbara; Deutsch, Andreas; Voss-Böhme, Anja

2017-08-11

Cancer cell invasion, dissemination, and metastasis have been linked to an epithelial-mesenchymal transition (EMT) of individual tumour cells. During EMT, adhesion molecules like E-cadherin are downregulated and the decrease of cell-cell adhesion allows tumour cells to dissociate from the primary tumour mass. This complex process depends on intracellular cues that are subject to genetic and epigenetic variability, as well as extrinsic cues from the local environment resulting in a spatial heterogeneity in the adhesive phenotype of individual tumour cells. Here, we use a novel mathematical model to study how adhesion heterogeneity, influenced by intrinsic and extrinsic factors, affects the dissemination of tumour cells from an epithelial cell population. The model is a multiscale cellular automaton that couples intracellular adhesion receptor regulation with cell-cell adhesion. Simulations of our mathematical model indicate profound effects of adhesion heterogeneity on tumour cell dissemination. In particular, we show that a large variation of intracellular adhesion receptor concentrations in a cell population reinforces cell dissemination, regardless of extrinsic cues mediated through the local cell density. However, additional control of adhesion receptor concentration through the local cell density, which can be assumed in healthy cells, weakens the effect. Furthermore, we provide evidence that adhesion heterogeneity can explain the remarkable differences in adhesion receptor concentrations of epithelial and mesenchymal phenotypes observed during EMT and might drive early dissemination of tumour cells. Our results suggest that adhesion heterogeneity may be a universal trigger to reinforce cell dissemination in epithelial cell populations. This effect can be at least partially compensated by a control of adhesion receptor regulation through neighbouring cells. Accordingly, our findings explain how both an increase in intra-tumour adhesion heterogeneity and the

Autophagy promotes degradation of internalized collagen and regulates distribution of focal adhesions to suppress cell adhesion

PubMed Central

Kawano, Shinichi; Esaki, Motohiro; Torisu, Kumiko; Matsuno, Yuichi; Kitazono, Takanari

2017-01-01

ABSTRACT Adhesion of cells to the extracellular matrix (ECM) via focal adhesions (FAs) is crucial for cell survival, migration, and differentiation. Although the regulation of FAs, including by integrins and the ECM, is important to cell behavior, how FAs are regulated is not well known. Autophagy is induced by both cell adhesion and cell detachment. Here, we showed that autophagosomes are located close to internalized collagen and paxillin, which is a well-known marker of FAs. Autophagy-deficient cells showed increased levels of internalized collagen compared with control cells. Moreover, paxillin exhibited a more peripheral distribution and the area of paxillin was increased, and adhesion-induced focal adhesion kinase signaling was impaired and adhesion was enhanced, in autophagy-deficient cells. These results suggest that autophagy suppressed cell adhesion by regulating internalized ECM and FAs. PMID:28970230

Neural control of colonic cell proliferation.

PubMed

Tutton, P J; Barkla, D H

1980-03-15

The mitotic rate in rat colonic crypts and in dimethylhydrazine-induced colonic carcinomas was measured using a stathmokinetic technique. In sympathectomized animals cell proliferation was retarded in the crypts but not in the tumors, whereas in animals treated with Metaraminol, a drug which releases norepinephrine from nerve terminals, crypt cell but not tumor cell proliferation was accelerated. Blockade of alpha-adrenoceptors also inhibited crypt cell proliferation. However, stimulation of beta-adrenoceptors inhibited and blockade of beta-adrenoceptors accelerated tumor cell proliferation without influencing crypt cell proliferation. Injection of either serotonin or histamine stimulated tumor but not crypt cell proliferation and blockade or serotonin receptors or histamine H2-receptors inhibited tumor cell proliferation. It is postulated that cell proliferation in the colonic crypts, like that in the jejunal crypts, is under both endocrine and autonomic neural control whereas colonic tumor cell division is subject to endocrine regulation alone.

CD147-targeting siRNA inhibits cell-matrix adhesion of human malignant melanoma cells by phosphorylating focal adhesion kinase.

PubMed

Nishibaba, Rie; Higashi, Yuko; Su, Juan; Furukawa, Tatsuhiko; Kawai, Kazuhiro; Kanekura, Takuro

2012-01-01

CD147/basigin, highly expressed on the surface of malignant tumor cells including malignant melanoma (MM) cells, plays a critical role in the invasiveness and metastasis of MM. Metastasis is an orchestrated process comprised of multiple steps including adhesion and invasion. Integrin, a major adhesion molecule, co-localizes with CD147/basigin on the cell surface. Using the human MM cell line A375 that highly expresses CD147/basigin, we investigated whether CD147/basigin is involved in adhesion in association with integrin. CD147/basigin was knocked-down using siRNA targeting CD147 to elucidate the role of CD147/basigin. Cell adhesion was evaluated by adhesion assay on matrix-coated plates. The localization of integrin was inspected under a confocal microscope and the expression and phosphorylation of focal adhesion kinase (FAK), a downstream kinase of integrin, were examined by western blot analysis. Silencing of CD147/basigin in A375 cells by siRNA induced the phosphorylation of FAK at Y397. Integrin identified on the surface of parental cells was distributed in a speckled fashion in the cytoplasm of CD147 knockdown cells, resulting in morphological changes from a round to a polygonal shape with pseudopodial protrusions. Silencing of CD147/basigin in A375 cells clearly weakened their adhesiveness to collagen I and IV. Our results suggest that CD147/basigin regulates the adhesion of MM cells to extracellular matrices and of integrin β1 signaling via the phosphorylation of FAK. © 2011 Japanese Dermatological Association.

Mesenchymal Stem/Multipotent Stromal Cells from Human Decidua Basalis Reduce Endothelial Cell Activation.

PubMed

Alshabibi, Manal A; Al Huqail, Al Joharah; Khatlani, Tanvir; Abomaray, Fawaz M; Alaskar, Ahmed S; Alawad, Abdullah O; Kalionis, Bill; Abumaree, Mohamed Hassan

2017-09-15

Recently, we reported the isolation and characterization of mesenchymal stem cells from the decidua basalis of human placenta (DBMSCs). These cells express a unique combination of molecules involved in many important cellular functions, which make them good candidates for cell-based therapies. The endothelium is a highly specialized, metabolically active interface between blood and the underlying tissues. Inflammatory factors stimulate the endothelium to undergo a change to a proinflammatory and procoagulant state (ie, endothelial cell activation). An initial response to endothelial cell activation is monocyte adhesion. Activation typically involves increased proliferation and enhanced expression of adhesion and inflammatory markers by endothelial cells. Sustained endothelial cell activation leads to a type of damage to the body associated with inflammatory diseases, such as atherosclerosis. In this study, we examined the ability of DBMSCs to protect endothelial cells from activation through monocyte adhesion, by modulating endothelial proliferation, migration, adhesion, and inflammatory marker expression. Endothelial cells were cocultured with DBMSCs, monocytes, monocyte-pretreated with DBMSCs and DBMSC-pretreated with monocytes were also evaluated. Monocyte adhesion to endothelial cells was examined following treatment with DBMSCs. Expression of endothelial cell adhesion and inflammatory markers was also analyzed. The interaction between DBMSCs and monocytes reduced endothelial cell proliferation and monocyte adhesion to endothelial cells. In contrast, endothelial cell migration increased in response to DBMSCs and monocytes. Endothelial cell expression of adhesion and inflammatory molecules was reduced by DBMSCs and DBMSC-pretreated with monocytes. The mechanism of reduced endothelial proliferation involved enhanced phosphorylation of the tumor suppressor protein p53. Our study shows for the first time that DBMSCs protect endothelial cells from activation by

Sulforaphane inhibits restenosis by suppressing inflammation and the proliferation of vascular smooth muscle cells.

PubMed

Kwon, Jin-Sook; Joung, Hosouk; Kim, Yong Sook; Shim, Young-Sun; Ahn, Youngkeun; Jeong, Myung Ho; Kee, Hae Jin

2012-11-01

Sulforaphane, a naturally occurring organosulfur compound in broccoli, has chemopreventive properties in cancer. However, the effects of sulforaphane in vascular diseases have not been examined. We therefore aimed to investigate the effects of sulforaphane on vascular smooth muscle cell (VSMC) proliferation and neointimal formation and the related mechanisms. The expression of vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1) was examined in VSMCs. The nuclear translocation of nuclear factor-κB (NF-κB) and GATA6 expression was examined in VSMCs and in a carotid artery injury model by Western blot and immunohistochemistry. We also investigated whether local delivery of sulforaphane affected neointimal formation. Sulforaphane inhibited the mRNA and protein expression of VCAM-1 induced by tumor necrosis factor (TNF)-α in VSMCs. Treatment of VSMCs with sulforaphane blocked TNF-α-induced IκBα degradation and NF-κB p65 and GATA6 expression. Furthermore, NF-κB p65 and GATA6 expression were reduced in sulforaphane-treated carotid injury sections. Notably, binding of GATA6 to the VCAM-1 promoter was dramatically reduced by sulforaphane. The MTT, BrdU incorporation, and in vitro scratch assays revealed that the proliferation and migration of VSMCs were reduced by sulforaphane. Furthermore, local administration of sulforaphane significantly reduced neointima formation 14 days after vascular injury in rats. Our results indicate that sulforaphane inhibits neointima formation via targeting of adhesion molecules through the suppression of NF-κB/GATA6. Furthermore, sulforaphane regulates migration and proliferation in VSMCs. Sulforaphane may be a potential therapeutic agent for preventing restenosis after vascular injury. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Mechanisms for Flow-Enhanced Cell Adhesion

PubMed Central

Zhu, Cheng; Yago, Tadayuki; Lou, Jizhong; Zarnitsyna, Veronika I.; McEver, Rodger P.

2009-01-01

Cell adhesion is mediated by specific receptor—ligand bonds. In several biological systems, increasing flow has been observed to enhance cell adhesion despite the increasing dislodging fluid shear forces. Flow-enhanced cell adhesion includes several aspects: flow augments the initial tethering of flowing cells to a stationary surface, slows the velocity and increases the regularity of rolling cells, and increases the number of rollingly adherent cells. Mechanisms for this intriguing phenomenon may include transport-dependent acceleration of bond formation and force-dependent deceleration of bond dissociation. The former includes three distinct transport modes: sliding of cell bottom on the surface, Brownian motion of the cell, and rotational diffusion of the interacting molecules. The latter involves a recently demonstrated counterintuitive behavior called catch bonds where force prolongs rather than shortens the lifetimes of receptor—ligand bonds. In this article, we summarize our recently published data that used dimensional analysis and mutational analysis to elucidate the above mechanisms for flow-enhanced leukocyte adhesion mediated by L-selectinligand interactions. PMID:18299992

Changes in E-cadherin rigidity sensing regulate cell adhesion.

PubMed

Collins, Caitlin; Denisin, Aleksandra K; Pruitt, Beth L; Nelson, W James

2017-07-18

Mechanical cues are sensed and transduced by cell adhesion complexes to regulate diverse cell behaviors. Extracellular matrix (ECM) rigidity sensing by integrin adhesions has been well studied, but rigidity sensing by cadherins during cell adhesion is largely unexplored. Using mechanically tunable polyacrylamide (PA) gels functionalized with the extracellular domain of E-cadherin (Ecad-Fc), we showed that E-cadherin-dependent epithelial cell adhesion was sensitive to changes in PA gel elastic modulus that produced striking differences in cell morphology, actin organization, and membrane dynamics. Traction force microscopy (TFM) revealed that cells produced the greatest tractions at the cell periphery, where distinct types of actin-based membrane protrusions formed. Cells responded to substrate rigidity by reorganizing the distribution and size of high-traction-stress regions at the cell periphery. Differences in adhesion and protrusion dynamics were mediated by balancing the activities of specific signaling molecules. Cell adhesion to a 30-kPa Ecad-Fc PA gel required Cdc42- and formin-dependent filopodia formation, whereas adhesion to a 60-kPa Ecad-Fc PA gel induced Arp2/3-dependent lamellipodial protrusions. A quantitative 3D cell-cell adhesion assay and live cell imaging of cell-cell contact formation revealed that inhibition of Cdc42, formin, and Arp2/3 activities blocked the initiation, but not the maintenance of established cell-cell adhesions. These results indicate that the same signaling molecules activated by E-cadherin rigidity sensing on PA gels contribute to actin organization and membrane dynamics during cell-cell adhesion. We hypothesize that a transition in the stiffness of E-cadherin homotypic interactions regulates actin and membrane dynamics during initial stages of cell-cell adhesion.

P38 delta MAPK promotes breast cancer progression and lung metastasis by enhancing cell proliferation and cell detachment.

PubMed

Wada, M; Canals, D; Adada, M; Coant, N; Salama, M F; Helke, K L; Arthur, J S; Shroyer, K R; Kitatani, K; Obeid, L M; Hannun, Y A

2017-11-23

The protein p38 mitogen-activated protein kinase (MAPK) delta isoform (p38δ) is a poorly studied member of the MAPK family. Data analysis from The Cancer Genome Atlas database revealed that p38δ is highly expressed in all types of human breast cancers. Using a human breast cancer tissue array, we confirmed elevation in cancer tissue. The breast cancer mouse model, MMTV-PyMT (PyMT), developed breast tumors with lung metastasis; however, mice deleted in p38δ (PyMT/p38δ -/- ) exhibited delayed primary tumor formation and highly reduced lung metastatic burden. At the cellular level, we demonstrate that targeting of p38δ in breast cancer cells, MCF-7 and MDA-MB-231 resulted in a reduced rate of cell proliferation. In addition, cells lacking p38δ also displayed an increased cell-matrix adhesion and reduced cell detachment. This effect on cell adhesion was molecularly supported by the regulation of the focal adhesion kinase by p38δ in the human breast cell lines. These studies define a previously unappreciated role for p38δ in breast cancer development and evolution by regulating tumor growth and altering metastatic properties. This study proposes MAPK p38δ protein as a key factor in breast cancer. Lack of p38δ resulted in reduced primary tumor size and blocked the metastatic potential to the lungs.

Culture Medium Supplements Derived from Human Platelet and Plasma: Cell Commitment and Proliferation Support

PubMed Central

Muraglia, Anita; Nguyen, Van Thi; Nardini, Marta; Mogni, Massimo; Coviello, Domenico; Dozin, Beatrice; Strada, Paolo; Baldelli, Ilaria; Formica, Matteo; Cancedda, Ranieri; Mastrogiacomo, Maddalena

2017-01-01

Present cell culture medium supplements, in most cases based on animal sera, are not fully satisfactory especially for the in vitro expansion of cells intended for human cell therapy. This paper refers to (i) an heparin-free human platelet lysate (PL) devoid of serum or plasma components (v-PL) and (ii) an heparin-free human serum derived from plasma devoid of PL components (Pl-s) and to their use as single components or in combination in primary or cell line cultures. Human mesenchymal stem cells (MSC) primary cultures were obtained from adipose tissue, bone marrow, and umbilical cord. Human chondrocytes were obtained from articular cartilage biopsies. In general, MSC expanded in the presence of Pl-s alone showed a low or no proliferation in comparison to cells grown with the combination of Pl-s and v-PL. Confluent, growth-arrested cells, either human MSC or human articular chondrocytes, treated with v-PL resumed proliferation, whereas control cultures, not supplemented with v-PL, remained quiescent and did not proliferate. Interestingly, signal transduction pathways distinctive of proliferation were activated also in cells treated with v-PL in the absence of serum, when cell proliferation did not occur, indicating that v-PL could induce the cell re-entry in the cell cycle (cell commitment), but the presence of serum proteins was an absolute requirement for cell proliferation to happen. Indeed, Pl-s alone supported cell growth in constitutively activated cell lines (U-937, HeLa, HaCaT, and V-79) regardless of the co-presence of v-PL. Plasma- and plasma-derived serum were equally able to sustain cell proliferation although, for cells cultured in adhesion, the Pl-s was more efficient than the plasma from which it was derived. In conclusion, the cells expanded in the presence of the new additives maintained their differentiation potential and did not show alterations in their karyotype. PMID:29209609

Cell adhesion and guidance by micropost-array chemical sensors

NASA Astrophysics Data System (ADS)

Pantano, Paul; Quah, Soo-Kim; Danowski, Kristine L.

2002-06-01

An array of ~50,000 individual polymeric micropost sensors was patterned across a glass coverslip by a photoimprint lithographic technique. Individual micropost sensors were ~3-micrometers tall and ~8-micrometers wide. The O2-sensitive micropost array sensors (MPASs) comprised a ruthenium complex encapsulated in a gas permeable photopolymerizable siloxane. The pH-sensitive MPASs comprised a fluorescein conjugate encapsulated in a photocrosslinkable poly(vinyl alcohol)-based polymer. PO2 and pH were quantitated by acquiring MPAS luminescence images with an epifluorescence microscope/charge coupled device imaging system. O2-sensitive MPASs displayed linear Stern-Volmer quenching behavior with a maximum Io/I of ~8.6. pH-sensitive MPASs displayed sigmoidal calibration curves with a pKa of ~5.8. The adhesion of undifferentiated rat pheochromocytoma (PC12) cells across these two polymeric surface types was investigated. The greatest PC12 cell proliferation and adhesion occurred across the poly(vinyl alcohol)-based micropost arrays relative to planar poly(vinyl alcohol)-based surfaces and both patterned and planar siloxane surfaces. An additional advantage of the patterned MPAS layers relative to planar sensing layers was the ability to direct the growth of biological cells. Preliminary data is presented whereby nerve growth factor-differentiated PC12 cells grew neurite-like processes that extended along paths defined by the micropost architecture.

In vitro cell culture, platelet adhesion tests and in vivo implant tests of plasma-polymerized para-xylene films

NASA Astrophysics Data System (ADS)

Chou, Chia-Man; Yeh, Chou-Ming; Chung, Chi-Jen; He, Ju-Liang

2013-09-01

Plasma-polymerized para-xylene (PPX) was developed in a previous study by adjusting the process parameters: pulse frequency of the power supply (ωp) and para-xylene monomer flow rate (fp). All the obtained PPX films exhibit an amorphous structure and present hydrophobicity (water contact angle ranging from 98.5° to 121.1°), higher film growth rate and good fibroblast cell proliferation. In this study, in vitro tests (fibroblast cell compatibility and platelet adhesion) and an in vivo animal study were performed by using PPX deposited industrial-grade silicone sheets (IGS) and compared with medical-grade silicone ones (MS), which were commonly manufactured into catheters or drainage tubes in clinical use. The results reveal that PPX deposited at high ωp or high fp, in comparison with MS, exhibit better cell proliferation and clearly shows less cell adhesion regardless of ωp and fp. PPX also exhibit a comparatively lower level of platelet adhesion than MS. In the animal study, PPX-coated IGS result in similar local tissue responses at 3, 7 and 28 days (short-term) and 84 days (long-term) after subcutaneous implantation the abdominal wall of rodents compared with respective responses to MS. These results suggest that PPX-coated industrial-grade silicone is one alternative to high cost medical-grade silicone.

Modulation of Cell Proliferation and Differentiation through Substrate-dependent Changes in Fibronectin Conformation

PubMed Central

García, Andrés J.; Vega, María D.; Boettiger, David

1999-01-01

Integrin-mediated cell adhesion to extracellular matrices provides signals essential for cell cycle progression and differentiation. We demonstrate that substrate-dependent changes in the conformation of adsorbed fibronectin (Fn) modulated integrin binding and controlled switching between proliferation and differentiation. Adsorption of Fn onto bacterial polystyrene (B), tissue culture polystyrene (T), and collagen (C) resulted in differences in Fn conformation as indicated by antibody binding. Using a biochemical method to quantify bound integrins in cultured cells, we found that differences in Fn conformation altered the quantity of bound α5 and β1 integrin subunits but not αv or β3. C2C12 myoblasts grown on these Fn-coated substrates proliferated to different levels (B > T > C). Immunostaining for muscle-specific myosin revealed minimal differentiation on B, significant levels on T, and extensive differentiation on C. Differentiation required binding to the RGD cell binding site in Fn and was blocked by antibodies specific for this site. Switching between proliferation and differentiation was controlled by the levels of α5β1 integrin bound to Fn, and differentiation was inhibited by anti-α5, but not anti-αv, antibodies, suggesting distinct integrin-mediated signaling pathways. Control of cell proliferation and differentiation through conformational changes in extracellular matrix proteins represents a versatile mechanism to elicit specific cellular responses for biological and biotechnological applications. PMID:10069818

Testicular Sertoli cells influence the proliferation and immunogenicity of co-cultured endothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fan, Ping, E-mail: fanpinggoodluck@163.com; He, Lan; Pu, Dan

Research highlights: {yields} The proliferation of dramatic increased by co-cultured with Sertoli cells. {yields} VEGF receptor-2 expression of ECs was up-regulated by co-cultured with Sertoli cells. {yields} The MHC expression of ECs induced by INF-{gamma} and IL-6, IL-8 and sICAM induced by TNF-{alpha} decreased respectively after co-cultured with Sertoli cells. {yields} ECs co-cultured with Sertoli cells also didn't increase the stimulation index of spleen lymphocytes. -- Abstract: The major problem of the application of endothelial cells (ECs) in transplantation is the lack of proliferation and their immunogenicity. In this study, we co-cultured ECs with Sertoli cells to monitor whether Sertolimore » cells can influence the proliferation and immunogenicity of co-cultured ECs. Sertoli cells were isolated from adult testicular tissue. ECs were divided into the control group and the experimental group, which included three sub-groups co-cultured with 1 x 10{sup 3}, 1 x 10{sup 4} or 1 x 10{sup 5} cell/ml of Sertoli cells. The growth and proliferation of ECs were observed microscopically, and the expression of vascular endothelial growth factor (VEGF) receptor-2 (KDR) was examined by Western blotting. In another experiment, ECs were divided into the control group, the single culture group and the co-culture group with the optimal concentration of Sertoli cells. After INF-{gamma} and TNF-{alpha} were added to the culture medium, MHC II antigen expression was detected by immunofluorescence staining and western blotting; interleukin (IL)-6, IL-8 and soluble intercellular adhesion molecule (sICAM) were measured in the culture medium by ELISA. We demonstrated that 1 x 10{sup 4} cell/ml Sertoli cells promoted the proliferation of co-cultured ECs more dramatically than that in other groups (P < 0.05). Western blotting showed that 1 x 10{sup 4} cell/ml of the Sertoli cells was most effective in the up-regulation of KDR expression in the co-cultured ECs (P < 0.05). Sertoli

Resveratrol Regulates Colorectal Cancer Cell Invasion by Modulation of Focal Adhesion Molecules

PubMed Central

Buhrmann, Constanze; Shayan, Parviz; Goel, Ajay; Shakibaei, Mehdi

2017-01-01

Resveratrol, a safe and multi-targeted agent, has been associated with suppression of survival, proliferation and metastasis of cancer, however, the underlying mechanisms for its anti-cancer activity, particularly on cellular signaling during cancer cell migration still remain poorly understood. We investigated the invasion response of two human colorectal cancer (CRC) cells (HCT116 and SW480) to resveratrol and studied the effect of specific pharmacological inhibitors, cytochalasin D (CytD) and focal adhesion kinase-inhibitor (FAK-I) on FAK, cell viability and migration in CRC. We found that resveratrol altered cell phenotype of both CRC cells, reduced cell viability and the results were comparable to FAK-I and CytD. These effects of resveratrol were associated with marked Sirt1 up-regulation, FAK down-regulation, inhibition of focal adhesion and potentiation of effects by combinatorial treatment of resveratrol and inhibitors. Interestingly, inhibition of FAK with FAK-I or treatment with CytD suppressed resveratrol-induced Sirt1 up-regulation and markedly down-regulated FAK expression. Resveratrol or combination treatment with inhibitors significantly activated caspase-3 and potentiated apoptosis. Moreover, resveratrol suppressed invasion and colony forming capacity, cell proliferation, β1-Integrin expression and activation of FAK of cells in alginate tumor microenvironment, similar to FAK-I or CytD. Finally, we demonstrated that resveratrol, FAK-I or CytD inhibited activation of NF-κB, suppressed NF-κB-dependent gene end-products involved in invasion, metastasis, and apoptosis; and these effects of resveratrol were potentiated by combination treatment with FAK-I or CytD. Our data illustrated that the anti-invasion effect of resveratrol by inhibition of FAK activity has a potential beneficial role in disease prevention and therapeutic management of CRC. PMID:28953264

Resveratrol Regulates Colorectal Cancer Cell Invasion by Modulation of Focal Adhesion Molecules.

PubMed

Buhrmann, Constanze; Shayan, Parviz; Goel, Ajay; Shakibaei, Mehdi

2017-09-27

Resveratrol, a safe and multi-targeted agent, has been associated with suppression of survival, proliferation and metastasis of cancer, however, the underlying mechanisms for its anti-cancer activity, particularly on cellular signaling during cancer cell migration still remain poorly understood. We investigated the invasion response of two human colorectal cancer (CRC) cells (HCT116 and SW480) to resveratrol and studied the effect of specific pharmacological inhibitors, cytochalasin D (CytD) and focal adhesion kinase-inhibitor (FAK-I) on FAK, cell viability and migration in CRC. We found that resveratrol altered cell phenotype of both CRC cells, reduced cell viability and the results were comparable to FAK-I and CytD. These effects of resveratrol were associated with marked Sirt1 up-regulation, FAK down-regulation, inhibition of focal adhesion and potentiation of effects by combinatorial treatment of resveratrol and inhibitors. Interestingly, inhibition of FAK with FAK-I or treatment with CytD suppressed resveratrol-induced Sirt1 up-regulation and markedly down-regulated FAK expression. Resveratrol or combination treatment with inhibitors significantly activated caspase-3 and potentiated apoptosis. Moreover, resveratrol suppressed invasion and colony forming capacity, cell proliferation, β1-Integrin expression and activation of FAK of cells in alginate tumor microenvironment, similar to FAK-I or CytD. Finally, we demonstrated that resveratrol, FAK-I or CytD inhibited activation of NF-κB, suppressed NF-κB-dependent gene end-products involved in invasion, metastasis, and apoptosis; and these effects of resveratrol were potentiated by combination treatment with FAK-I or CytD. Our data illustrated that the anti-invasion effect of resveratrol by inhibition of FAK activity has a potential beneficial role in disease prevention and therapeutic management of CRC.

Titanium dioxide nanotubes functionalized with Cratylia mollis seed lectin, Cramoll, enhanced osteoblast-like cells adhesion and proliferation.

PubMed

Oliveira, Weslley F; Silva, Germana M M; Cabral Filho, Paulo E; Fontes, Adriana; Oliveira, Maria D L; Andrade, César A S; Silva, Márcia V; Coelho, Luana C B B; Machado, Giovanna; Correia, Maria T S

2018-09-01

An alternative to accelerate the osseointegration on titanium dioxide nanotubes (TNTs) used in osseointegrated implants is through the functionalization of these nanostructured surfaces with biomolecules. In this work, we immobilized a lectin with recognized mitogenic activity, the Cramoll lectin, extracted from Cratylia mollis seeds, on surfaces modified by TNTs. For the immobilization of Cramoll on TNTs surfaces, we used the Layer-by-Layer technique (LbL) by growing five alternate layers of poly(allylamine) hydrochloride (PAH) and poly(acrylic) acid (PAA); lastly we incubated the lectin, at different concentrations, with the TNTs-LbL. Before and after the immobilization procedures, the substrate surfaces were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and, electrochemical impedance spectroscopy (EIS). We also evaluated the Cramoll activity after immobilization on TNTs by using the lectin interaction with ovalbumin. The lectin did not lose its biological activity, even after immobilization onto nanotubular arrays. In addition, we observed an increase osteoblast-like cell adhesion on the TNTs-LbL-Cramoll system when compared to the bare TNTs surfaces. Moreover, a significative cell proliferation was identified on the substrates when Cramoll was immobilized at concentrations of 80, 160 and 320 μg/mL after 48 h of incubation by using the resazurin assay. Our results suggest that Cramoll was efficiently immobilized on a nanotubular array and this new platform presents a great potential to be tested in implantology. Copyright © 2018 Elsevier B.V. All rights reserved.

RELM-β promotes human pulmonary artery smooth muscle cell proliferation via FAK-stimulated surviving

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Chunlong, E-mail: lclmd@sina.com; Li, Xiaohui; Luo, Qiong

Resistin-like molecule-β (RELM-β), focal adhesion kinase (FAK), and survivin may be involved in the proliferation of cultured human pulmonary artery smooth muscle cells (HPAMSCs), which is involved in pulmonary hypertension. HPAMSCs were treated with human recombinant RELM-β (rhRELM-β). siRNAs against FAK and survivin were transfected into cultured HPASMCs. Expression of FAK and survivin were examined by RT-PCR and western blot. Immunofluorescence was used to localize FAK. Flow cytometry was used to examine cell cycle distribution and cell death. Compared to the control group, all rhRELM-β-treated groups demonstrated significant increases in the expression of FAK and survivin (P<0.05). rhRELM-β significantly increasedmore » the proportion of HPASMCs in the S phase and decreased the proportion in G0/G1. FAK siRNA down-regulated survivin expression while survivin siRNA did not affect FAK expression. FAK siRNA effectively inhibited FAK and survivin expression in RELM-β-treated HPASMCs and partially suppressed cell proliferation. RELM-β promoted HPASMC proliferation and upregulated FAK and survivin expression. In conclusion, results suggested that FAK is upstream of survivin in the signaling pathway mediating cell proliferation. FAK seems to be important in RELM-β-induced HPASMC proliferation, partially by upregulating survivin expression. - Highlights: • rhRELM-β increased the expression of FAK and survivin. • rhRELM-β increased the proportion of HPASMCs in the S phase. • FAK is upstream of survivin in the signaling pathway mediating cell proliferation. • FAK is important in RELM-β-induced HPASMC proliferation, partly via survivin.« less

Changes in E-cadherin rigidity sensing regulate cell adhesion

PubMed Central

Collins, Caitlin; Pruitt, Beth L.; Nelson, W. James

2017-01-01

Mechanical cues are sensed and transduced by cell adhesion complexes to regulate diverse cell behaviors. Extracellular matrix (ECM) rigidity sensing by integrin adhesions has been well studied, but rigidity sensing by cadherins during cell adhesion is largely unexplored. Using mechanically tunable polyacrylamide (PA) gels functionalized with the extracellular domain of E-cadherin (Ecad-Fc), we showed that E-cadherin–dependent epithelial cell adhesion was sensitive to changes in PA gel elastic modulus that produced striking differences in cell morphology, actin organization, and membrane dynamics. Traction force microscopy (TFM) revealed that cells produced the greatest tractions at the cell periphery, where distinct types of actin-based membrane protrusions formed. Cells responded to substrate rigidity by reorganizing the distribution and size of high-traction-stress regions at the cell periphery. Differences in adhesion and protrusion dynamics were mediated by balancing the activities of specific signaling molecules. Cell adhesion to a 30-kPa Ecad-Fc PA gel required Cdc42- and formin-dependent filopodia formation, whereas adhesion to a 60-kPa Ecad-Fc PA gel induced Arp2/3-dependent lamellipodial protrusions. A quantitative 3D cell–cell adhesion assay and live cell imaging of cell–cell contact formation revealed that inhibition of Cdc42, formin, and Arp2/3 activities blocked the initiation, but not the maintenance of established cell–cell adhesions. These results indicate that the same signaling molecules activated by E-cadherin rigidity sensing on PA gels contribute to actin organization and membrane dynamics during cell–cell adhesion. We hypothesize that a transition in the stiffness of E-cadherin homotypic interactions regulates actin and membrane dynamics during initial stages of cell–cell adhesion. PMID:28674019

Enrichment of Female Germline Stem Cells from Mouse Ovaries Using the Differential Adhesion Method.

PubMed

Wu, Meng; Xiong, Jiaqiang; Ma, Lingwei; Lu, Zhiyong; Qin, Xian; Luo, Aiyue; Zhang, Jinjin; Xie, Huan; Shen, Wei; Wang, Shixuan

2018-04-28

The isolation and establishment of female germline stem cells (FGSCs) is controversial because of questions regarding the reliability and stability of the isolation method using antibody targeting mouse vasa homologue (MVH), and the molecular mechanism of FGSCs self-renewal remains unclear. Thus, there needs to be a simple and reliable method for sorting FGSCs to study them. We applied the differential adhesion method to enrich FGSCs (DA-FGSCs) from mouse ovaries. Through four rounds of purification and 7-9 subsequent passages, DA-FGSC lines were established. In addition, we assessed the role of the phosphoinositide-3 kinase (PI3K)-AKT pathway in regulating FGSC self-renewal. The obtained DA-FGSCs spontaneously differentiated into oocyte-like cells in vitro and formed functional eggs in vivo that were fertilized and produced healthy offspring. AKT was rapidly phosphorylated when the proliferation rate of FGSCs increased after 10 passages, and the addition of a chemical PI3K inhibitor prevented FGSCs self-renewal. Furthermore, over-expression of AKT-induced proliferation and differentiation of FGSCs, c-Myc, Oct-4 and Gdf-9 levels were increased. The differential adhesion method provides a more feasible approach and is an easier procedure to establish FGSC lines than traditional methods. The AKT pathway plays an important role in regulation of the proliferation and maintenance of FGSCs. These findings could help promote stem cell studies and provide a better understanding of causes of ovarian infertility, thereby providing potential treatments for infertility. © 2018 The Author(s). Published by S. Karger AG, Basel.

Immobilization of Cell-Adhesive Laminin Peptides in Degradable PEGDA Hydrogels Influences Endothelial Cell Tubulogenesis

PubMed Central

Ali, Saniya; Saik, Jennifer E.; Gould, Dan J.; Dickinson, Mary E.

2013-01-01

Abstract Attachment, spreading, and organization of endothelial cells into tubule networks are mediated by interactions between cells in the extracellular microenvironment. Laminins are key extracellular matrix components and regulators of cell adhesion, migration, and proliferation. In this study, laminin-derived peptides were conjugated to poly(ethylene glycol) (PEG) monoacrylate and covalently incorporated into degradable PEG diacrylate (PEGDA) hydrogels to investigate the influence of these peptides on endothelial cellular adhesion and function in organizing into tubule networks. Degradable PEGDA hydrogels were synthesized by incorporating a matrix metalloproteinase (MMP)–sensitive peptide, GGGPQGIWGQGK (abbreviated PQ), into the polymer backbone. The secretion of MMP-2 and MMP-9 by endothelial cells promotes polymer degradation and consequently cell migration. We demonstrate the formation of extensive networks of tubule-like structures by encapsulated human umbilical vein endothelial cells in hydrogels with immobilized synthetic peptides. The resulting structures were stabilized by pericyte precursor cells (10T1/2s) in vitro. During tubule formation and stabilization, extracellular matrix proteins such as collagen IV and laminin were deposited. Tubules formed in the matrix of metalloproteinase sensitive hydrogels were visualized from 7 days to 4 weeks in response to different combination of peptides. Moreover, hydrogels functionalized with laminin peptides and transplanted in a mouse cornea supported the ingrowth and attachment of endothelial cells to the hydrogel during angiogenesis. Results of this study illustrate the use of laminin-derived peptides as potential candidates for modification of biomaterials to support angiogenesis. PMID:23914330

The Epithelial Cell Adhesion Molecule EpCAM Is Required for Epithelial Morphogenesis and Integrity during Zebrafish Epiboly and Skin Development

PubMed Central

Slanchev, Krasimir; Carney, Thomas J.; Stemmler, Marc P.; Koschorz, Birgit; Amsterdam, Adam; Schwarz, Heinz; Hammerschmidt, Matthias

2009-01-01

The aberrant expression of the transmembrane protein EpCAM is associated with tumor progression, affecting different cellular processes such as cell–cell adhesion, migration, proliferation, differentiation, signaling, and invasion. However, the in vivo function of EpCAM still remains elusive due to the lack of genetic loss-of-function studies. Here, we describe epcam (tacstd) null mutants in zebrafish. Maternal-zygotic mutants display compromised basal protrusive activity and epithelial morphogenesis in cells of the enveloping layer (EVL) during epiboly. In partial redundancy with E-cadherin (Ecad), EpCAM made by EVL cells is further required for cell–cell adhesion within the EVL and, possibly, for proper attachment of underlying deep cells to the inner surface of the EVL, thereby also affecting deep cell epiboly movements. During later development, EpCAM per se becomes indispensable for epithelial integrity within the periderm of the skin, secondarily leading to disrupted morphology of the underlying basal epidermis and moderate hyper-proliferation of skin cells. On the molecular level, EVL cells of epcam mutant embryos display reduced levels of membranous Ecad, accompanied by an enrichment of tight junction proteins and a basal extension of apical junction complexes (AJCs). Our data suggest that EpCAM acts as a partner of E-cadherin to control adhesiveness and integrity as well as plasticity and morphogenesis within simple epithelia. In addition, EpCAM is required for the interaction of the epithelia with underlying cell layers. PMID:19609345

Scalable topographies to support proliferation and Oct4 expression by human induced pluripotent stem cells

PubMed Central

Reimer, Andreas; Vasilevich, Aliaksei; Hulshof, Frits; Viswanathan, Priyalakshmi; van Blitterswijk, Clemens A.; de Boer, Jan; Watt, Fiona M.

2016-01-01

It is well established that topographical features modulate cell behaviour, including cell morphology, proliferation and differentiation. To define the effects of topography on human induced pluripotent stem cells (iPSC), we plated cells on a topographical library containing over 1000 different features in medium lacking animal products (xeno-free). Using high content imaging, we determined the effect of each topography on cell proliferation and expression of the pluripotency marker Oct4 24 h after seeding. Features that maintained Oct4 expression also supported proliferation and cell-cell adhesion at 24 h, and by 4 days colonies of Oct4-positive, Sox2-positive cells had formed. Computational analysis revealed that small feature size was the most important determinant of pluripotency, followed by high wave number and high feature density. Using this information we correctly predicted whether any given topography within our library would support the pluripotent state at 24 h. This approach not only facilitates the design of substrates for optimal human iPSC expansion, but also, potentially, identification of topographies with other desirable characteristics, such as promoting differentiation. PMID:26757610

Tight junction-based epithelial microenvironment and cell proliferation.

PubMed

Tsukita, S; Yamazaki, Y; Katsuno, T; Tamura, A; Tsukita, S

2008-11-24

Belt-like tight junctions (TJs), referred to as zonula occludens, have long been regarded as a specialized differentiation of epithelial cell membranes. They are required for cell adhesion and paracellular barrier functions, and are now thought to be partly involved in fence functions and in cell polarization. Recently, the molecular bases of TJs have gradually been unveiled. TJs are constructed by TJ strands, whose basic frameworks are composed of integral membrane proteins with four transmembrane domains, designated claudins. The claudin family is supposedly composed of at least 24 members in mice and humans. Other types of integral membrane proteins with four transmembrane domains, namely occludin and tricellulin, as well as the single transmembrane proteins, JAMs (junctional adhesion molecules) and CAR (coxsackie and adenovirus receptor), are associated with TJ strands, and the high-level organization of TJ strands is likely to be established by membrane-anchored scaffolding proteins, such as ZO-1/2. Recent functional analyses of claudins in cell cultures and in mice have suggested that claudin-based TJs may have pivotal functions in the regulation of the epithelial microenvironment, which is critical for various biological functions such as control of cell proliferation. These represent the dawn of 'Barriology' (defined by Shoichiro Tsukita as the science of barriers in multicellular organisms). Taken together with recent reports regarding changes in claudin expression levels, understanding the regulation of the TJ-based microenvironment system will provide new insights into the regulation of polarization in the respect of epithelial microenvironment system and new viewpoints for developing anticancer strategies.

Characterization of collagen II fibrils containing biglycan and their effect as a coating on osteoblast adhesion and proliferation.

PubMed

Douglas, Timothy; Heinemann, Sascha; Hempel, Ute; Mietrach, Carolin; Knieb, Christiane; Bierbaum, Susanne; Scharnweber, Dieter; Worch, Hartmut

2008-04-01

Collagen has been used as a coating material for titanium-based implants for bone contact and as a component of scaffolds for bone tissue engineering. In general collagen type I has been used, however very little attention has been focussed on collagen type II. Collagen-based coatings and scaffolds have been enhanced by the incorporation of the glycosaminoglycan chondroitin sulphate (CS), however the proteglycan biglycan, which is found in bone and contains glycosaminoglycan chains consisting of CS, has not been used as a biomaterial component. The study had the following aims: firstly, five different collagen II preparations were compared with regard to their ability to bind CS and biglycan and the changes in fibril morphology thereby induced. Secondly, the effects of biglycan on the adhesion of primary rat osteoblasts (rO) as well as the proliferation of rO, primary human osteoblasts (hO) and the osteoblast-like cell line 7F2 were studied by culturing the cells on surfaces coated with collagen II fibrils containing biglycan. Fibrils of the collagen II preparation which bound the most biglycan were used to coat titanium surfaces. Bare titanium, titanium coated with collagen II fibrils and titanium coated with collagen II fibrils containing biglycan were compared. It was found that different collagen II preparations showed different affinities for CS and biglycan. In four of the five preparations tested, biglycan reduced fibril diameter, however the ability of a preparation to bind more biglycan did not appear to lead to a greater reduction in fibril diameter. Fibrils containing biglycan promoted the formation of focal adhesions by rO and significantly enhanced the proliferation of hO but not of rO or 7F2 cells. These results should encourage further investigation of biglycan as a component of collagen-based scaffolds and/or coatings.

The conveyor belt hypothesis for thymocyte migration: participation of adhesion and de-adhesion molecules.

PubMed

Villa-Verde, D M; Calado, T C; Ocampo, J S; Silva-Monteiro, E; Savino, W

1999-05-01

Thymocyte differentiation is the process by which bone marrow-derived precursors enter the thymus, proliferate, rearrange the genes and express the corresponding T cell receptors, and undergo positive and/or negative selection, ultimately yielding mature T cells that will represent the so-called T cell repertoire. This process occurs in the context of cell migration, whose cellular and molecular basis is still poorly understood. Kinetic studies favor the idea that these cells leave the organ in an ordered pattern, as if they were moving on a conveyor belt. We have recently proposed that extracellular matrix glycoproteins, such as fibronectin, laminin and type IV collagen, among others, produced by non-lymphoid cells both in the cortex and in the medulla, would constitute a macromolecular arrangement allowing differentiating thymocytes to migrate. Here we discuss the participation of both molecules with adhesive and de-adhesive properties in the intrathymic T cell migration. Functional experiments demonstrated that galectin-3, a soluble beta-galactoside-binding lectin secreted by thymic microenvironmental cells, is a likely candidate for de-adhesion proteins by decreasing thymocyte interaction with the thymic microenvironment.

Extracellular matrix collagen alters cell proliferation and cell cycle progression of human uterine leiomyoma smooth muscle cells.

PubMed

Koohestani, Faezeh; Braundmeier, Andrea G; Mahdian, Arash; Seo, Jane; Bi, JiaJia; Nowak, Romana A

2013-01-01

Uterine leiomyomas (ULs) are benign tumors occurring in the majority of reproductive aged women. Despite the high prevalence of these tumors, little is known about their etiology. A hallmark of ULs is the excessive deposition of extracellular matrix (ECM), primarily collagens. Collagens are known to modulate cell behavior and function singularly or through interactions with integrins and growth factor-mediated mitogenic pathways. To better understand the pathogenesis of ULs and the role of ECM collagens in their growth, we investigated the interaction of leiomyoma smooth muscle cells (LSMCs) with two different forms of collagen, non-polymerized collagen (monomeric) and polymerized collagen (fibrillar), in the absence or presence of platelet-derived growth factor (PDGF), an abundant growth factor in ULs. Primary cultures of human LSMCS from symptomatic patients were grown on these two different collagen matrices and their morphology, cytoskeletal organization, cellular proliferation, and signaling pathways were evaluated. Our results showed that LSMCs had distinct morphologies on the different collagen matrices and their basal as well as PDGF-stimulated proliferation varied on these matrices. These differences in proliferation were accompanied by changes in cell cycle progression and p21, an inhibitory cell cycle protein. In addition we found alterations in the phosphorylation of focal adhesion kinase, cytoskeletal reorganization, and activation of the mitogen activated protein kinase (MAPK) signaling pathway. In conclusion, our results demonstrate a direct effect of ECM on the proliferation of LSMCs through interplay between the collagen matrix and the PDGF-stimulated MAPK pathway. In addition, these findings will pave the way for identifying novel therapeutic approaches for ULs that target ECM proteins and their signaling pathways in ULs.

Extracellular Matrix Collagen Alters Cell Proliferation and Cell Cycle Progression of Human Uterine Leiomyoma Smooth Muscle Cells

PubMed Central

Koohestani, Faezeh; Braundmeier, Andrea G.; Mahdian, Arash; Seo, Jane; Bi, JiaJia; Nowak, Romana A.

2013-01-01

Uterine leiomyomas (ULs) are benign tumors occurring in the majority of reproductive aged women. Despite the high prevalence of these tumors, little is known about their etiology. A hallmark of ULs is the excessive deposition of extracellular matrix (ECM), primarily collagens. Collagens are known to modulate cell behavior and function singularly or through interactions with integrins and growth factor-mediated mitogenic pathways. To better understand the pathogenesis of ULs and the role of ECM collagens in their growth, we investigated the interaction of leiomyoma smooth muscle cells (LSMCs) with two different forms of collagen, non-polymerized collagen (monomeric) and polymerized collagen (fibrillar), in the absence or presence of platelet-derived growth factor (PDGF), an abundant growth factor in ULs. Primary cultures of human LSMCS from symptomatic patients were grown on these two different collagen matrices and their morphology, cytoskeletal organization, cellular proliferation, and signaling pathways were evaluated. Our results showed that LSMCs had distinct morphologies on the different collagen matrices and their basal as well as PDGF-stimulated proliferation varied on these matrices. These differences in proliferation were accompanied by changes in cell cycle progression and p21, an inhibitory cell cycle protein. In addition we found alterations in the phosphorylation of focal adhesion kinase, cytoskeletal reorganization, and activation of the mitogen activated protein kinase (MAPK) signaling pathway. In conclusion, our results demonstrate a direct effect of ECM on the proliferation of LSMCs through interplay between the collagen matrix and the PDGF-stimulated MAPK pathway. In addition, these findings will pave the way for identifying novel therapeutic approaches for ULs that target ECM proteins and their signaling pathways in ULs. PMID:24040420

Inhibition of PTP1B disrupts cell-cell adhesion and induces anoikis in breast epithelial cells.

PubMed

Hilmarsdottir, Bylgja; Briem, Eirikur; Halldorsson, Skarphedinn; Kricker, Jennifer; Ingthorsson, Sævar; Gustafsdottir, Sigrun; Mælandsmo, Gunhild M; Magnusson, Magnus K; Gudjonsson, Thorarinn

2017-05-11

Protein tyrosine phosphatase 1B (PTP1B) is a well-known inhibitor of insulin signaling pathways and inhibitors against PTP1B are being developed as promising drug candidates for treatment of obesity. PTP1B has also been linked to breast cancer both as a tumor suppressor and as an oncogene. Furthermore, PTP1B has been shown to be a regulator of cell adhesion and migration in normal and cancer cells. In this study, we analyzed the PTP1B expression in normal breast tissue, primary breast cells and the breast epithelial cell line D492. In normal breast tissue and primary breast cells, PTP1B is widely expressed in both epithelial and stromal cells, with highest expression in myoepithelial cells and fibroblasts. PTP1B is widely expressed in branching structures generated by D492 when cultured in 3D reconstituted basement membrane (3D rBM). Inhibition of PTP1B in D492 and another mammary epithelial cell line HMLE resulted in reduced cell proliferation and induction of anoikis. These changes were seen when cells were cultured both in monolayer and in 3D rBM. PTP1B inhibition affected cell attachment, expression of cell adhesion proteins and actin polymerization. Moreover, epithelial to mesenchymal transition (EMT) sensitized cells to PTP1B inhibition. A mesenchymal sublines of D492 and HMLE (D492M and HMLEmes) were more sensitive to PTP1B inhibition than D492 and HMLE. Reversion of D492M to an epithelial state using miR-200c-141 restored resistance to detachment induced by PTP1B inhibition. In conclusion, we have shown that PTP1B is widely expressed in the human breast gland with highest expression in myoepithelial cells and fibroblasts. Inhibition of PTP1B in D492 and HMLE affects cell-cell adhesion and induces anoikis-like effects. Finally, cells with an EMT phenotype are more sensitive to PTP1B inhibitors making PTP1B a potential candidate for further studies as a target for drug development in cancer involving the EMT phenotype.

Single cell adhesion assay using computer controlled micropipette.

PubMed

Salánki, Rita; Hős, Csaba; Orgovan, Norbert; Péter, Beatrix; Sándor, Noémi; Bajtay, Zsuzsa; Erdei, Anna; Horvath, Robert; Szabó, Bálint

2014-01-01

Cell adhesion is a fundamental phenomenon vital for all multicellular organisms. Recognition of and adhesion to specific macromolecules is a crucial task of leukocytes to initiate the immune response. To gain statistically reliable information of cell adhesion, large numbers of cells should be measured. However, direct measurement of the adhesion force of single cells is still challenging and today's techniques typically have an extremely low throughput (5-10 cells per day). Here, we introduce a computer controlled micropipette mounted onto a normal inverted microscope for probing single cell interactions with specific macromolecules. We calculated the estimated hydrodynamic lifting force acting on target cells by the numerical simulation of the flow at the micropipette tip. The adhesion force of surface attached cells could be accurately probed by repeating the pick-up process with increasing vacuum applied in the pipette positioned above the cell under investigation. Using the introduced methodology hundreds of cells adhered to specific macromolecules were measured one by one in a relatively short period of time (∼30 min). We blocked nonspecific cell adhesion by the protein non-adhesive PLL-g-PEG polymer. We found that human primary monocytes are less adherent to fibrinogen than their in vitro differentiated descendants: macrophages and dendritic cells, the latter producing the highest average adhesion force. Validation of the here introduced method was achieved by the hydrostatic step-pressure micropipette manipulation technique. Additionally the result was reinforced in standard microfluidic shear stress channels. Nevertheless, automated micropipette gave higher sensitivity and less side-effect than the shear stress channel. Using our technique, the probed single cells can be easily picked up and further investigated by other techniques; a definite advantage of the computer controlled micropipette. Our experiments revealed the existence of a sub-population of

Silencing of the integrin-linked kinase gene suppresses the proliferation, migration and invasion of pancreatic cancer cells (Panc-1).

PubMed

Zhu, Xiang-Yu; Liu, Ning; Liu, Wei; Song, Shao-Wei; Guo, Ke-Jian

2012-04-01

Integrin-linked kinase (ILK) is an ankyrin repeat-containing serine-threonine protein kinase that is involved in the regulation of integrin-mediated processes such as cancer cell proliferation, migration and invasion. In this study, we examined the effect of a lentivirus-mediated knockdown of ILK on the proliferation, migration and invasion of pancreatic cancer (Panc-1) cells. Immunohistochemical staining showed that ILK expression was enhanced in pancreatic cancer tissue. The silencing of ILK in human Panc-1 cells led to cell cycle arrest in the G0/G1 phase and delayed cell proliferation, in addition to down-regulating cell migration and invasion. The latter effects were mediated by up-regulating the expression of E-cadherin, a key protein in cell adhesion. These findings indicate that ILK may be a new diagnostic marker for pancreatic cancer and that silencing ILK could be a potentially useful therapeutic approach for treating pancreatic cancer.

Various Surface Treatments to Implant Provisional Restorations and Their Effect on Epithelial Cell Adhesion: A Comparative In Vitro Study.

PubMed

Luchinskaya, Darya; Du, Rong; Owens, David M; Tarnow, Dennis; Bittner, Nurit

2017-02-01

The aim of this in vitro study was to investigate the ability of epithelial cells to attach to or proliferate on various mechanical or chemical surface treatments of an implant provisional material. Polyethyl methacrylate discs 10 mm in diameter and ∼0.2 to 0.75 mm in width were used in the study. Experimental discs were treated with either a mechanical (pumice, varnish for shine, or high polishing) or a chemical agent (alcohol, chlorhexidine, or steam) to provide cleaning and/or polishing. Using primary human epidermal keratinocytes, experiments were performed to test the adhesion or proliferation of cells on the discs with various surface treatments. Scanning electron microscope analysis, rhodamine staining, and cell counting using a hemocytometer corroborated all findings and illustrated that the highest cell adhesion was found to be in the smooth surface treatment groups and the poorest adhesion was found to be in the rough surface groups and chemical treatment group. Within the limitations of this study, the following clinical protocol is recommended for finishing, polishing, and disinfecting implant provisional restorations: coarse, medium, fine pumice → high polishing (if desired) → steam. It is recommended to avoid applying varnish in the perimucosal area near the epithelium. This study could establish the most appropriate way to handle provisional restorations in the peri-implant sulcus for improved soft tissue health, esthetics, and long-term stability.

Friction-Controlled Traction Force in Cell Adhesion

PubMed Central

Pompe, Tilo; Kaufmann, Martin; Kasimir, Maria; Johne, Stephanie; Glorius, Stefan; Renner, Lars; Bobeth, Manfred; Pompe, Wolfgang; Werner, Carsten

2011-01-01

The force balance between the extracellular microenvironment and the intracellular cytoskeleton controls the cell fate. We report a new (to our knowledge) mechanism of receptor force control in cell adhesion originating from friction between cell adhesion ligands and the supporting substrate. Adherent human endothelial cells have been studied experimentally on polymer substrates noncovalently coated with fluorescent-labeled fibronectin (FN). The cellular traction force correlated with the mobility of FN during cell-driven FN fibrillogenesis. The experimental findings have been explained within a mechanistic two-dimensional model of the load transfer at focal adhesion sites. Myosin motor activity in conjunction with sliding of FN ligands noncovalently coupled to the surface of the polymer substrates is shown to result in a controlled traction force of adherent cells. We conclude that the friction of adhesion ligands on the supporting substrate is important for mechanotransduction and cell development of adherent cells in vitro and in vivo. PMID:22004739

Actin-Based Adhesion Modules Mediate Cell Interactions with the Extracellular Matrix and Neighboring Cells.

PubMed

Bachir, Alexia I; Horwitz, Alan Rick; Nelson, W James; Bianchini, Julie M

2017-07-05

Cell adhesions link cells to the extracellular matrix (ECM) and to each other and depend on interactions with the actin cytoskeleton. Both cell-ECM and cell-cell adhesion sites contain discrete, yet overlapping, functional modules. These modules establish physical associations with the actin cytoskeleton, locally modulate actin organization and dynamics, and trigger intracellular signaling pathways. Interplay between these modules generates distinct actin architectures that underlie different stages, types, and functions of cell-ECM and cell-cell adhesions. Actomyosin contractility is required to generate mature, stable adhesions, as well as to sense and translate the mechanical properties of the cellular environment into changes in cell organization and behavior. Here, we review the organization and function of different adhesion modules and how they interact with the actin cytoskeleton. We highlight the molecular mechanisms of mechanotransduction in adhesions and how adhesion molecules mediate cross talk between cell-ECM and cell-cell adhesion sites. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

Modeling keratinocyte wound healing dynamics: Cell-cell adhesion promotes sustained collective migration.

PubMed

Nardini, John T; Chapnick, Douglas A; Liu, Xuedong; Bortz, David M

2016-07-07

The in vitro migration of keratinocyte cell sheets displays behavioral and biochemical similarities to the in vivo wound healing response of keratinocytes in animal model systems. In both cases, ligand-dependent Epidermal Growth Factor Receptor (EGFR) activation is sufficient to elicit collective cell migration into the wound. Previous mathematical modeling studies of in vitro wound healing assays assume that physical connections between cells have a hindering effect on cell migration, but biological literature suggests a more complicated story. By combining mathematical modeling and experimental observations of collectively migrating sheets of keratinocytes, we investigate the role of cell-cell adhesion during in vitro keratinocyte wound healing assays. We develop and compare two nonlinear diffusion models of the wound healing process in which cell-cell adhesion either hinders or promotes migration. Both models can accurately fit the leading edge propagation of cell sheets during wound healing when using a time-dependent rate of cell-cell adhesion strength. The model that assumes a positive role of cell-cell adhesion on migration, however, is robust to changes in the leading edge definition and yields a qualitatively accurate density profile. Using RNAi for the critical adherens junction protein, α-catenin, we demonstrate that cell sheets with wild type cell-cell adhesion expression maintain migration into the wound longer than cell sheets with decreased cell-cell adhesion expression, which fails to exhibit collective migration. Our modeling and experimental data thus suggest that cell-cell adhesion promotes sustained migration as cells pull neighboring cells into the wound during wound healing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Small-molecule inhibitors of FGFR, integrins and FAK selectively decrease L1CAM-stimulated glioblastoma cell motility and proliferation.

PubMed

Anderson, Hannah J; Galileo, Deni S

2016-06-01

The cell adhesion/recognition protein L1CAM (L1; CD171) has previously been shown to act through integrin, focal adhesion kinase (FAK) and fibroblast growth factor receptor (FGFR) signaling pathways to increase the motility and proliferation of glioblastoma cells in an autocrine/paracrine manner. Here, we investigated the effects of clinically relevant small-molecule inhibitors of the integrin, FAK and FGFR signaling pathways on glioblastoma-derived cells to determine their effectiveness and selectivity for diminishing L1-mediated stimulation. The effects of the FGFR inhibitor PD173074, the FAK inhibitors PF431396 and Y15 and the αvβ3/αvβ5 integrin inhibitor cilengitide were assessed in L1-positive and L1-negative variants of the human glioblastoma-derived cell lines T98G and U-118 MG. Their motility and proliferation were quantified using time-lapse microscopy and DNA content/cell cycle analyses, respectively. The application of all four inhibitors resulted in reductions in L1-mediated motility and proliferation rates of L1-positive glioblastoma-derived cells, down to the level of L1-negative cells when used at nanomolar concentrations, whereas no or much smaller reductions in these rates were obtained in L1-negative cells. In addition, we found that single inhibitor treatment resulted in maximum effects (i.e., combinations of FAK or integrin inhibitors with the FGFR inhibitor were rarely more effective). These results suggest that FAK may act as a point of convergence between the integrin and FGFR signaling pathways stimulated by L1 in these cells. We here show for the first time that small-molecule inhibitors of FGFR, integrins and FAK effectively and selectively abolish L1-stimulated migration and proliferation of glioblastoma-derived cells. Our results suggest that these inhibitors have the potential to reduce the aggressiveness of high-grade gliomas expressing L1.

Cadherin-23 Mediates Heterotypic Cell-Cell Adhesion between Breast Cancer Epithelial Cells and Fibroblasts

PubMed Central

Apostolopoulou, Maria; Ligon, Lee

2012-01-01

In the early stages of breast cancer metastasis, epithelial cells penetrate the basement membrane and invade the surrounding stroma, where they encounter fibroblasts. Paracrine signaling between fibroblasts and epithelial tumor cells contributes to the metastatic cascade, but little is known about the role of adhesive contacts between these two cell types in metastasis. Here we show that MCF-7 breast cancer epithelial cells and normal breast fibroblasts form heterotypic adhesions when grown together in co-culture, as evidenced by adhesion assays. PCR and immunoblotting show that both cell types express multiple members of the cadherin superfamily, including the atypical cadherin, cadherin-23, when grown in isolation and in co-culture. Immunocytochemistry experiments show that cadherin-23 localizes to homotypic adhesions between MCF-7 cells and also to heterotypic adhesions between the epithelial cells and fibroblasts, and antibody inhibition and RNAi experiments show that cadherin-23 plays a role in mediating these adhesive interactions. Finally, we show that cadherin-23 is upregulated in breast cancer tissue samples, and we hypothesize that heterotypic adhesions mediated by this atypical cadherin may play a role in the early stages of metastasis. PMID:22413011

Pravastatin and simvastatin inhibit the adhesion, replication and proliferation of Toxoplasma gondii (RH strain) in HeLa cells.

PubMed

Sanfelice, Raquel Arruda; da Silva, Suelen Santos; Bosqui, Larissa Rodrigues; Miranda-Sapla, Milena Menegazzo; Barbosa, Bellisa Freitas; Silva, Rafaela José; Ferro, Eloísa A Vieira; Panagio, Luciano Aparecido; Navarro, Italmar Teodorico; Bordignon, Juliano; Conchon-Costa, Ivete; Pavanelli, Wander Rogerio; Almeida, Ricardo Sergio; Costa, Idessania Nazareth

2017-03-01

The conventional treatment for toxoplasmosis with pyrimethamine and sulfadiazine shows toxic effects to the host, and it is therefore necessary to search for new drugs. Some studies suggest the use of statins, which inhibit cholesterol synthesis in humans and also the initial processes of isoprenoid biosynthesis in the parasite. Thus, the objective of this study was to evaluate the activity of the statins pravastatin and simvastatin in HeLa cells infected in vitro with the RH strain of T. gondii. HeLa cells (1×10 5 ) were infected with T. gondii tachyzoites (5×10 5 ) following two different treatment protocols. In the first protocol, T. gondii tachyzoites were pretreated with pravastatin (50 and 100μg/mL) and simvastatin (1.56 and 3.125μg/mL) for 30min prior to infection. In the second, HeLa cells were first infected (5×10 5 ) with tachyzoites and subsequently treated with pravastatin and simvastatin for 24h at the concentrations noted above. Initially, we evaluated the cytotoxicity of drugs by the MTT assay, number of tachyzoites adhered to cells, number of infected cells, and viability of tachyzoites by trypan blue exclusion. The supernatant of the cell cultures was collected post-treatment for determination of the pattern of Th1/Th2/Th17 cytokines by cytometric bead array. There was no cytotoxicity to HeLa cells with 50 and 100μg/mL pravastatin and 1.56 and 3.125μg/mL simvastatin. There was no change in the viability of tachyzoites that received pretreatment. Regarding the pre- and post-treatment of the cells with pravastatin and simvastatin alone, there was a reduction in adhesion, invasion and proliferation of cells to T. gondii. As for the production of cytokines, we found that IL-6 and IL-17 were significantly reduced in cells infected with T. gondii and treated with pravastatin and simvastatin, when compared to control. Based on these results, we can infer that pravastatin and simvastatin alone possess antiproliferative effects on tachyzoites forms

Effects of active and inactive phospholipase D2 on signal transduction, adhesion, migration, invasion, and metastasis in EL4 lymphoma cells.

PubMed

Knoepp, Stewart M; Chahal, Manpreet S; Xie, Yuhuan; Zhang, Zhihong; Brauner, Daniel J; Hallman, Mark A; Robinson, Stephanie A; Han, Shujie; Imai, Masaki; Tomlinson, Stephen; Meier, Kathryn E

2008-09-01

The phosphatidylcholine-using phospholipase D (PLD) isoform PLD2 is widely expressed in mammalian cells and is activated in response to a variety of promitogenic agonists. In this study, active and inactive hemagglutinin-tagged human PLD2 (HA-PLD2) constructs were stably expressed in an EL4 cell line lacking detectable endogenous PLD1 or PLD2. The overall goal of the study was to examine the roles of PLD2 in cellular signal transduction and cell phenotype. HA-PLD2 confers PLD activity that is activated by phorbol ester, ionomycin, and okadaic acid. Proliferation and Erk activation are unchanged in cells transfected with active PLD2; proliferation rate is decreased in cells expressing inactive PLD2. Basal tyrosine phosphorylation of focal adhesion kinase (FAK) is increased in cells expressing active PLD2, as is phosphorylation of Akt; inactive PLD2 has no effect. Expression of active PLD2 is associated with increased spreading and elongation of cells on tissue culture plastic, whereas inactive PLD2 inhibits cell spreading. Inactive PLD2 also inhibits cell adhesion, migration, and serum-induced invasion. Cells expressing active PLD2 form metastases in syngeneic mice, as do the parental cells; cells expressing inactive PLD2 form fewer metastases than parental cells. In summary, active PLD2 enhances FAK phosphorylation, Akt activation, and cell invasion in EL4 lymphoma cells, whereas inactive PLD2 exerts inhibitory effects on adhesion, migration, invasion, and tumor formation. Overall, expression of active PLD2 enhances processes favorable to lymphoma cell metastasis, whereas expression of inactive PLD2 inhibits metastasis.

[Molecular mechanism involved in adhesion of monocytes to endothelial cells induced by nicotine and Porphyromonas gingivalis-LPS].

PubMed

Wang, Yi-xiang; An, Na; Ouyang, Xiang-ying

2015-10-18

To investigate molecular mechanism involved in nicotine in combination with Porphyromonas gingivalis (P.g) caused monocyte-endothelial cell adhesion. The effect of nicotine, P.g-lipopolysaccharide (P.g-LPS) and their combination on the proliferation of U937 cells was determined by CCK-8 method. Interleukin-6 (IL-6) expression was investigated by real-time PCR after U937 cells were treated with nicotine, P.g-LPS and their combination. In human umbilical vein endothelial cells (HUVECs), the expressions of monocyte chemoattractant protein CCL-8 and adhesion molecules including vascular cell adhesion molecule 1 (Vcam-1), very late antigen 4 alpha (VLA4α), tumor necrosis factor receptor superfamily member 4 (OX40) and OX40 ligand (OX40L) were detected by real-time PCR or Western blotting assays after HUVEC cells were treated with nicotine, P.g-LPS and their combination. Adhesion of monocytes to endothelial cells was detected after the HUVECs and U937 cells were stimulated with nicotine, P.g-LPS and their combination, respectively. P.g-LPS did not affect the proliferative ability of nicotine in U937 cells. However, the ability of P.g-LPS induced IL-6 expression was inhibited by 100 μmol/L nicotine in U937 cells. In HUVECs, the expressions of CCL-8, Vcam-1, VLA4α, OX40 and OX40L were significantly up-regulated by nicotine and P.g-LPS combination compared with nicotine alone, P.g-LPS alone and the untreated control. Adhesion of monocytes to HUVECs results showed that the two types of cells treated with nicotine in combination with P.g-LPS could markedly increase the adhesion ability of monocytes to HUVECs. P.g-LPS in combination with nicotine could recruit monocytes to endothelial lesion through up-regulation of CCL-8, and promote adhesion of monocytes to endothelial cells through enhancement of Vcam-1/VLA4α and OX40/OX40L interactions, which could be involved in the initiation and development of atherosclerosis.

Identification of methyl violet 2B as a novel blocker of focal adhesion kinase signaling pathway in cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Hwan; Translational Research Center for Protein Function Control; Kim, Nam Doo

2013-07-26

Highlights: •FAK signaling cascade in cancer cells is profoundly inhibited by methyl violet 2B. •Methyl violet 2B identified by virtual screening is a novel allosteric FAK inhibitor. •Methyl violet 2B possesses extremely high kinase selectivity. •Methyl violet 2B suppresses strongly the proliferation of cancer cells. •Methyl violet 2B inhibits focal adhesion, invasion and migration of cancer cells. -- Abstract: The focal adhesion kinase (FAK) signaling cascade in cancer cells was profoundly inhibited by methyl violet 2B identified with the structure-based virtual screening. Methyl violet 2B was shown to be a non-competitive inhibitor of full-length FAK enzyme vs. ATP. It turnedmore » out that methyl violet 2B possesses extremely high kinase selectivity in biochemical kinase profiling using a large panel of kinases. Anti-proliferative activity measurement against several different cancer cells and Western blot analysis showed that this substance is capable of suppressing significantly the proliferation of cancer cells and is able to strongly block FAK/AKT/MAPK signaling pathways in a dose dependent manner at low nanomolar concentration. Especially, phosphorylation of Tyr925-FAK that is required for full activation of FAK was nearly completely suppressed even with 1 nM of methyl violet 2B in A375P cancer cells. To the best of our knowledge, it has never been reported that methyl violet possesses anti-cancer effects. Moreover, methyl violet 2B significantly inhibited FER kinase phosphorylation that activates FAK in cell. In addition, methyl violet 2B was found to induce cell apoptosis and to exhibit strong inhibitory effects on the focal adhesion, invasion, and migration of A375P cancer cells at low nanomolar concentrations. Taken together, these results show that methyl violet 2B is a novel, potent and selective blocker of FAK signaling cascade, which displays strong anti-proliferative activities against a variety of human cancer cells and suppresses

An Inducible Endothelial Cell Surface Glycoprotein Mediates Melanoma Adhesion

NASA Astrophysics Data System (ADS)

Rice, G. Edgar; Bevilacqua, Michael P.

1989-12-01

Hematogenous metastasis requires the arrest and extravasation of blood-borne tumor cells, possibly involving direct adhesive interactions with vascular endothelium. Cytokine activation of cultured human endothelium increases adhesion of melanoma and carcinoma cell lines. An inducible 110-kD endothelial cell surface glycoprotein, designated INCAM-110, appears to mediate adhesion of melanoma cells. In addition, an inducible endothelial receptor for neutrophils, ELAM-1, supports the adhesion of a human colon carcinoma cell line. Thus, activation of vascular endothelium in vivo that results in increased expression of INCAM-110 and ELAM-1 may promote tumor cell adhesion and affect the incidence and distribution of metastases.

Single-cell force spectroscopy of pili-mediated adhesion

NASA Astrophysics Data System (ADS)

Sullan, Ruby May A.; Beaussart, Audrey; Tripathi, Prachi; Derclaye, Sylvie; El-Kirat-Chatel, Sofiane; Li, James K.; Schneider, Yves-Jacques; Vanderleyden, Jos; Lebeer, Sarah; Dufrêne, Yves F.

2013-12-01

Although bacterial pili are known to mediate cell adhesion to a variety of substrates, the molecular interactions behind this process are poorly understood. We report the direct measurement of the forces guiding pili-mediated adhesion, focusing on the medically important probiotic bacterium Lactobacillus rhamnosus GG (LGG). Using non-invasive single-cell force spectroscopy (SCFS), we quantify the adhesion forces between individual bacteria and biotic (mucin, intestinal cells) or abiotic (hydrophobic monolayers) surfaces. On hydrophobic surfaces, bacterial pili strengthen adhesion through remarkable nanospring properties, which - presumably - enable the bacteria to resist high shear forces under physiological conditions. On mucin, nanosprings are more frequent and adhesion forces larger, reflecting the influence of specific pili-mucin bonds. Interestingly, these mechanical responses are no longer observed on human intestinal Caco-2 cells. Rather, force curves exhibit constant force plateaus with extended ruptures reflecting the extraction of membrane nanotethers. These single-cell analyses provide novel insights into the molecular mechanisms by which piliated bacteria colonize surfaces (nanosprings, nanotethers), and offer exciting avenues in nanomedicine for understanding and controlling the adhesion of microbial cells (probiotics, pathogens).

Single Cell Adhesion Assay Using Computer Controlled Micropipette

PubMed Central

Salánki, Rita; Hős, Csaba; Orgovan, Norbert; Péter, Beatrix; Sándor, Noémi; Bajtay, Zsuzsa; Erdei, Anna; Horvath, Robert; Szabó, Bálint

2014-01-01

Cell adhesion is a fundamental phenomenon vital for all multicellular organisms. Recognition of and adhesion to specific macromolecules is a crucial task of leukocytes to initiate the immune response. To gain statistically reliable information of cell adhesion, large numbers of cells should be measured. However, direct measurement of the adhesion force of single cells is still challenging and today’s techniques typically have an extremely low throughput (5–10 cells per day). Here, we introduce a computer controlled micropipette mounted onto a normal inverted microscope for probing single cell interactions with specific macromolecules. We calculated the estimated hydrodynamic lifting force acting on target cells by the numerical simulation of the flow at the micropipette tip. The adhesion force of surface attached cells could be accurately probed by repeating the pick-up process with increasing vacuum applied in the pipette positioned above the cell under investigation. Using the introduced methodology hundreds of cells adhered to specific macromolecules were measured one by one in a relatively short period of time (∼30 min). We blocked nonspecific cell adhesion by the protein non-adhesive PLL-g-PEG polymer. We found that human primary monocytes are less adherent to fibrinogen than their in vitro differentiated descendants: macrophages and dendritic cells, the latter producing the highest average adhesion force. Validation of the here introduced method was achieved by the hydrostatic step-pressure micropipette manipulation technique. Additionally the result was reinforced in standard microfluidic shear stress channels. Nevertheless, automated micropipette gave higher sensitivity and less side-effect than the shear stress channel. Using our technique, the probed single cells can be easily picked up and further investigated by other techniques; a definite advantage of the computer controlled micropipette. Our experiments revealed the existence of a sub

Hyaluronic acid influence on platelet-induced airway smooth muscle cell proliferation.

PubMed

Svensson Holm, Ann-Charlotte B; Bengtsson, Torbjörn; Grenegård, Magnus; Lindström, Eva G

2012-03-10

Hyaluronic acid (HA) is one of the main components of the extracellular matrix (ECM) and is expressed throughout the body including the lung and mostly in areas surrounding proliferating and migrating cells. Furthermore, platelets have been implicated as important players in the airway remodelling process, e.g. due to their ability to induce airway smooth muscle cell (ASMC) proliferation. The aim of the present study was to investigate the role of HA, the HA-binding surface receptor CD44 and focal adhesion kinase (FAK) in platelet-induced ASMC proliferation. Proliferation of ASMC was measured using the MTS-assay, and we found that the CD44 blocking antibody and the HA synthase inhibitor 4-Methylumbelliferone (4-MU) significantly inhibited platelet-induced ASMC proliferation. The interaction between ASMC and platelets was studied by fluorescent staining of F-actin. In addition, the ability of ASMC to synthesise HA was investigated by fluorescent staining using biotinylated HA-binding protein and a streptavidin conjugate. We observed that ASMC produced HA and that a CD44 blocking antibody and 4-MU significantly inhibited platelet binding to the area surrounding the ASMC. Furthermore, the FAK-inhibitor PF 573228 inhibited platelet-induced ASMC proliferation. Co-culture of ASMC and platelets also resulted in increased phosphorylation of FAK as detected by Western blot analysis. In addition, 4-MU significantly inhibited the increased FAK-phosphorylation. In conclusion, our findings demonstrate that ECM has the ability to influence platelet-induced ASMC proliferation. Specifically, we propose that HA produced by ASMC is recognised by platelet CD44. The platelet/HA interaction is followed by FAK activation and increased proliferation of co-cultured ASMC. We also suggest that the mitogenic effect of platelets represents a potential important and novel mechanism that may contribute to airway remodelling. Copyright © 2011 Elsevier Inc. All rights reserved.

Neural cell adhesion molecule-deficient beta-cell tumorigenesis results in diminished extracellular matrix molecule expression and tumour cell-matrix adhesion.

PubMed

Håkansson, Joakim; Xian, Xiaojie; He, Liqun; Ståhlberg, Anders; Nelander, Sven; Samuelsson, Tore; Kubista, Mikael; Semb, Henrik

2005-01-01

To understand by which mechanism neural cell adhesion molecule (N-CAM) limits beta tumour cell disaggregation and dissemination, we searched for potential downstream genes of N-CAM during beta tumour cell progression by gene expression profiling. Here, we show that N-CAM-deficient beta-cell tumorigenesis is associated with changes in the expression of genes involved in cell-matrix adhesion and cytoskeletal dynamics, biological processes known to affect the invasive and metastatic behaviour of tumour cells. The extracellular matrix (ECM) molecules emerged as the primary target, i.e. N-CAM deficiency resulted in down-regulated mRNA expression of a broad range of ECM molecules. Consistent with this result, deficient deposition of major ECM stromal components, such as fibronectin, laminin 1 and collagen IV, was observed. Moreover, N-CAM-deficient tumour cells displayed defective matrix adhesion. These results offer a potential mechanism for tumour cell disaggregation during N-CAM-deficient beta tumour cell progression. Prospective consequences of these findings for the role of N-CAM in beta tumour cell dissemination are discussed.

A Review of Cell Adhesion Studies for Biomedical and Biological Applications.

PubMed

Khalili, Amelia Ahmad; Ahmad, Mohd Ridzuan

2015-08-05

Cell adhesion is essential in cell communication and regulation, and is of fundamental importance in the development and maintenance of tissues. The mechanical interactions between a cell and its extracellular matrix (ECM) can influence and control cell behavior and function. The essential function of cell adhesion has created tremendous interests in developing methods for measuring and studying cell adhesion properties. The study of cell adhesion could be categorized into cell adhesion attachment and detachment events. The study of cell adhesion has been widely explored via both events for many important purposes in cellular biology, biomedical, and engineering fields. Cell adhesion attachment and detachment events could be further grouped into the cell population and single cell approach. Various techniques to measure cell adhesion have been applied to many fields of study in order to gain understanding of cell signaling pathways, biomaterial studies for implantable sensors, artificial bone and tooth replacement, the development of tissue-on-a-chip and organ-on-a-chip in tissue engineering, the effects of biochemical treatments and environmental stimuli to the cell adhesion, the potential of drug treatments, cancer metastasis study, and the determination of the adhesion properties of normal and cancerous cells. This review discussed the overview of the available methods to study cell adhesion through attachment and detachment events.

The roles of cell adhesion molecules in tumor suppression and cell migration: a new paradox.

PubMed

Moh, Mei Chung; Shen, Shali

2009-01-01

In addition to mediating cell adhesion, many cell adhesion molecules act as tumor suppressors. These proteins are capable of restricting cell growth mainly through contact inhibition. Alterations of these cell adhesion molecules are a common event in cancer. The resulting loss of cell-cell and/or cell-extracellular matrix adhesion promotes cell growth as well as tumor dissemination. Therefore, it is conventionally accepted that cell adhesion molecules that function as tumor suppressors are also involved in limiting tumor cell migration. Paradoxically, in 2005, we identified an immunoglobulin superfamily cell adhesion molecule hepaCAM that is able to suppress cancer cell growth and yet induce migration. Almost concurrently, CEACAM1 was verified to co-function as a tumor suppressor and invasion promoter. To date, the reason and mechanism responsible for this exceptional phenomenon remain unclear. Nevertheless, the emergence of these intriguing cell adhesion molecules with conflicting roles may open a new chapter to the biological significance of cell adhesion molecules.

The pan phosphoinositide 3-kinase/mammalian target of rapamycin inhibitor SAR245409 (voxtalisib/XL765) blocks survival, adhesion and proliferation of primary chronic lymphocytic leukemia cells.

PubMed

Thijssen, R; Ter Burg, J; van Bochove, G G W; de Rooij, M F M; Kuil, A; Jansen, M H; Kuijpers, T W; Baars, J W; Virone-Oddos, A; Spaargaren, M; Egile, C; van Oers, M H J; Eldering, E; Kersten, M J; Kater, A P

2016-02-01

The phosphoinositide 3-kinases (PI3Ks) are critical components of the B-cell receptor (BCR) pathway and have an important role in the pathobiology of chronic lymphocytic leukemia (CLL). Inhibitors of PI3Kδ block BCR-mediated cross-talk between CLL cells and the lymph node microenvironment and provide significant clinical benefit to CLL patients. However, the PI3Kδ inhibitors applied thus far have limited direct impact on leukemia cell survival and thus are unlikely to eradicate the disease. The use of inhibitors of multiple isoforms of PI3K might lead to deeper remissions. Here we demonstrate that the pan-PI3K/mammalian target of rapamycin inhibitor SAR245409 (voxtalisib/XL765) was more pro-apoptotic to CLL cells--irrespective of their ATM/p53 status--than PI3Kα or PI3Kδ isoform selective inhibitors. Furthermore, SAR245409 blocked CLL survival, adhesion and proliferation. Moreover, SAR245409 was a more potent inhibitor of T-cell-mediated production of cytokines, which support CLL survival. Taken together, our in vitro data provide a rationale for the evaluation of a pan-PI3K inhibitor in CLL patients.

The influence of high intensity terahertz radiation on mammalian cell adhesion, proliferation and differentiation.

PubMed

Williams, Rachel; Schofield, Amy; Holder, Gareth; Downes, Joan; Edgar, David; Harrison, Paul; Siggel-King, Michele; Surman, Mark; Dunning, David; Hill, Stephen; Holder, David; Jackson, Frank; Jones, James; McKenzie, Julian; Saveliev, Yuri; Thomsen, Neil; Williams, Peter; Weightman, Peter

2013-01-21

Understanding the influence of exposure of biological systems to THz radiation is becoming increasingly important. There is some evidence to suggest that THz radiation can influence important activities within mammalian cells. This study evaluated the influence of the high peak power, low average power THz radiation produced by the ALICE (Daresbury Laboratory, UK) synchrotron source on human epithelial and embryonic stem cells. The cells were maintained under standard tissue culture conditions, during which the THz radiation was delivered directly into the incubator for various exposure times. The influence of the THz radiation on cell morphology, attachment, proliferation and differentiation was evaluated. The study demonstrated that there was no difference in any of these parameters between irradiated and control cell cultures. It is suggested that under these conditions the cells are capable of compensating for any effects caused by exposure to THz radiation with the peak powers levels employed in these studies.

TiO2 nanoparticles disrupt cell adhesion and the architecture of cytoskeletal networks of human osteoblast-like cells in a size dependent manner.

PubMed

Ibrahim, Mohamed; Schoelermann, Julia; Mustafa, Kamal; Cimpan, Mihaela R

2018-04-30

Human exposure to titanium dioxide nanoparticles (nano-TiO 2 ) is increasing. An internal source of nano-TiO 2 is represented by titanium-based orthopedic and dental implants can release nanoparticles (NPs) upon abrasion. Little is known about how the size of NPs influences their interaction with cytoskeletal protein networks and the functional/homeostatic consequences that might follow at the implant-bone interface with regard to osteoblasts. We investigated the effects of size of anatase nano-TiO 2 on SaOS-2 human osteoblast-like cells exposed to clinically relevant concentrations (0.05, 0.5, 5 mg/L) of 5 and 40 nm spherical nano-TiO 2 . Cell viability and proliferation, adhesion, spread and migration were assessed, as well as the orientation of actin and microtubule cytoskeletal networks. The phosphorylation of focal adhesion kinase (p-FAK Y397 ) and the expression of vinculin in response to nano-TiO 2 were also assessed. Treatment with nano-TiO 2 disrupted the actin and microtubule cytoskeletal networks leading to morphological modifications of SaOS-2 cells. The phosphorylation of p-FAK Y397 and the expression of vinculin were also modified depending on the particle size, which affected cell adhesion. Consequently, the cell migration was significantly impaired in the 5 nm-exposed cells compared to unexposed cells. The present work shows that the orientation of cytoskeletal networks and the focal adhesion proteins and subsequently the adhesion, spread and migration of SaOS-2 cells were affected by the selected nano-TiO 2 in a size dependent manner. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

A Review of Cell Adhesion Studies for Biomedical and Biological Applications

PubMed Central

Ahmad Khalili, Amelia; Ahmad, Mohd Ridzuan

2015-01-01

Cell adhesion is essential in cell communication and regulation, and is of fundamental importance in the development and maintenance of tissues. The mechanical interactions between a cell and its extracellular matrix (ECM) can influence and control cell behavior and function. The essential function of cell adhesion has created tremendous interests in developing methods for measuring and studying cell adhesion properties. The study of cell adhesion could be categorized into cell adhesion attachment and detachment events. The study of cell adhesion has been widely explored via both events for many important purposes in cellular biology, biomedical, and engineering fields. Cell adhesion attachment and detachment events could be further grouped into the cell population and single cell approach. Various techniques to measure cell adhesion have been applied to many fields of study in order to gain understanding of cell signaling pathways, biomaterial studies for implantable sensors, artificial bone and tooth replacement, the development of tissue-on-a-chip and organ-on-a-chip in tissue engineering, the effects of biochemical treatments and environmental stimuli to the cell adhesion, the potential of drug treatments, cancer metastasis study, and the determination of the adhesion properties of normal and cancerous cells. This review discussed the overview of the available methods to study cell adhesion through attachment and detachment events. PMID:26251901

Proliferating cell nuclear antigen (PCNA): a new marker to study human colonic cell proliferation.

PubMed Central

Kubben, F J; Peeters-Haesevoets, A; Engels, L G; Baeten, C G; Schutte, B; Arends, J W; Stockbrügger, R W; Blijham, G H

1994-01-01

Immunohistochemistry of the S phase related proliferating cell nuclear antigen (PCNA) was studied as an alternative to ex-vivo bromodeoxyuridine (BrdU) immunohistochemistry for assessment of human colonic cell proliferation. From 16 subjects without colonic disease biopsy specimens were collected from five different sites along the colorectum and processed for BrdU and PCNA immunohistochemistry. The mean proliferation index of PCNA was significantly higher at 133% of the value obtained with BrdU. There was, however, a good correlation between the results from both techniques (r = 0.6275; p < 0.05). Decrease in proliferation index along the colorectum was seen with both staining methods but was clearer with PCNA immunohistochemistry (caecum/ascending colon v rectum: 12.0 v 7.2; p < 0.004). The total number of crypt cells also decreased from proximal to distal (134 to 128; p < 0.06) but at no site correlated significantly with the proliferation index. It is concluded that in clinical cell kinetic studies staining for PCNA may serve as an attractive alternative to the BrdU incorporation assay. Images Figure 4 PMID:7909785

Facile modulation of cell adhesion to a poly(ethylene glycol) diacrylate film with incorporation of polystyrene nano-spheres.

PubMed

Yang, Wenguang; Yu, Haibo; Li, Gongxin; Wang, Yuechao; Liu, Lianqing

2016-12-01

Poly(ethylene glycol) diacrylate (PEGDA) is a common hydrogel that has been actively investigated for various tissue engineering applications owing to its biocompatibility and excellent mechanical properties. However, the native PEGDA films are known for their bio-inertness which can hinder cell adhesion, thereby limiting their applications in tissue engineering and biomedicine. Recently, nano composite technology has become a particularly hot topic, and has led to the development of new methods for delivering desired properties to nanomaterials. In this study, we added polystyrene nano-spheres (PS) into a PEGDA solution to synthesize a nano-composite film and evaluated its characteristics. The experimental results showed that addition of the nanospheres to the PEGDA film not only resulted in modification of the mechanical properties and surface morphology but further improved the adhesion of cells on the film. The tensile modulus showed clear dependence on the addition of PS, which enhanced the mechanical properties of the PEGDA-PS film. We attribute the high stiffness of the hybrid hydrogel to the formation of additional cross-links between polymeric chains and the nano-sphere surface in the network. The effect of PS on cell adhesion and proliferation was evaluated in L929 mouse fibroblast cells that were seeded on the surface of various PEGDA-PS films. Cells density increased with a larger PS concentration, and the cells displayed a spreading morphology on the hybrid films, which promoted cell proliferation. Impressively, cellular stiffness could also be modulated simply by tuning the concentration of nano-spheres. Our results indicate that the addition of PS can effectively tailor the physical and biological properties of PEGDA as well as the mechanical properties of cells, with benefits for biomedical and biotechnological applications.

Cell-cell adhesion in the cnidaria: insights into the evolution of tissue morphogenesis.

PubMed

Magie, Craig R; Martindale, Mark Q

2008-06-01

Cell adhesion is a major aspect of cell biology and one of the fundamental processes involved in the development of a multicellular animal. Adhesive mechanisms, both cell-cell and between cell and extracellular matrix, are intimately involved in assembling cells into the three-dimensional structures of tissues and organs. The modulation of adhesive complexes could therefore be seen as a central component in the molecular control of morphogenesis, translating information encoded within the genome into organismal form. The availability of whole genomes from early-branching metazoa such as cnidarians is providing important insights into the evolution of adhesive processes by allowing for the easy identification of the genes involved in adhesion in these organisms. Discovery of the molecular nature of cell adhesion in the early-branching groups, coupled with comparisons across the metazoa, is revealing the ways evolution has tinkered with this vital cellular process in the generation of the myriad forms seen across the animal kingdom.

The use of biomaterials for cell function enhancement: acceleration of fibroblast migration and promotion of stem cell proliferation

NASA Astrophysics Data System (ADS)

Qin, Sisi

, while remained constant for the cells on the flat surfaces. The increased speed on the 8microm fiber surfaces could be correlated with a 20% increase in the nuclear deformation, and a decrease around 30% in the number of focal adhesion during the same observation period. RNA expression of Myosin IIA, a protein which complexes to the actin and is responsible for exertion of traction forces during migration was not upregulated during this process. On the other hand, histochemical staining of Myosin IIA showed that the protein had re-organized into large fibers which spanned the length of the cells. Observation of the cell morphology indicated that a new mode of motion had been established. Rather than the classical retraction of the cytoplasm followed by center of mass translation, which was observed on the flat surfaces, the cells were now moving by a contractile motion around the nucleus similar to that found in muscular motion. This mode was found to be more efficient when undergoing oriented motion. In addition to orientation, surface mechanics are also important in the tissue regeneration process. This study demonstrated that mechanical factors are important for the maintenance of pluripotency and control of proliferation rates. CD34+ hematopoietic stem cells (HSCs) were transduced with ICD (intracellular domain)-Notch and plated on gelatin hydrogels, whose moduli were controlled by the crosslinking ratio. On the softer hydrogel, a synergy was achieved which resulted in more than a five-fold increase in proliferation and a four-fold increase in the preservation of stemness, while HSCs maintained their ability to differentiate into multiple blood cell lineages. These results point the way for achieving clinically significant expansion of human HSCs.

KSA Antigen Ep-CAM Mediates Cell–Cell Adhesion of Pancreatic Epithelial Cells: Morphoregulatory Roles in Pancreatic Islet Development

PubMed Central

Cirulli, V.; Crisa, L.; Beattie, G.M.; Mally, M.I.; Lopez, A.D.; Fannon, A.; Ptasznik, A.; Inverardi, L.; Ricordi, C.; Deerinck, T.; Ellisman, M.; Reisfeld, R.A.; Hayek, A.

1998-01-01

Cell adhesion molecules (CAMs) are important mediators of cell–cell interactions and regulate cell fate determination by influencing growth, differentiation, and organization within tissues. The human pancarcinoma antigen KSA is a glycoprotein of 40 kD originally identified as a marker of rapidly proliferating tumors of epithelial origin. Interestingly, most normal epithelia also express this antigen, although at lower levels, suggesting that a dynamic regulation of KSA may occur during cell growth and differentiation. Recently, evidence has been provided that this glycoprotein may function as an epithelial cell adhesion molecule (Ep-CAM). Here, we report that Ep-CAM exhibits the features of a morphoregulatory molecule involved in the development of human pancreatic islets. We demonstrate that Ep-CAM expression is targeted to the lateral domain of epithelial cells of the human fetal pancreas, and that it mediates calcium-independent cell–cell adhesion. Quantitative confocal immunofluorescence in fetal pancreata identified the highest levels of Ep-CAM expression in developing islet-like cell clusters budding from the ductal epithelium, a cell compartment thought to comprise endocrine progenitors. A surprisingly reversed pattern was observed in the human adult pancreas, displaying low levels of Ep-CAM in islet cells and high levels in ducts. We further demonstrate that culture conditions promoting epithelial cell growth induce upregulation of Ep-CAM, whereas endocrine differentiation of fetal pancreatic epithelial cells, transplanted in nude mice, is associated with a downregulation of Ep-CAM expression. In addition, a blockade of Ep-CAM function by KS1/4 mAb induced insulin and glucagon gene transcription and translation in fetal pancreatic cell clusters. These results indicate that developmentally regulated expression and function of Ep-CAM play a morphoregulatory role in pancreatic islet ontogeny. PMID:9508783

Loss of intercellular adhesion activates a transition from low- to high-grade human squamous cell carcinoma.

PubMed

Margulis, Alexander; Zhang, Weitian; Alt-Holland, Addy; Pawagi, Sujata; Prabhu, Padmaja; Cao, Jian; Zucker, Stanley; Pfeiffer, Laurence; Garfield, Jacqueline; Fusenig, Norbert E; Garlick, Jonathan A

2006-02-15

The relationship between loss of intercellular adhesion and the biologic properties of human squamous cell carcinoma is not well understood. We investigated how abrogation of E-cadherin-mediated adhesion influenced the behavior and phenotype of squamous cell carcinoma in 3D human tissues. Cell-cell adhesion was disrupted in early-stage epithelial tumor cells (HaCaT-II-4) through expression of a dominant-negative form of E-cadherin (H-2Kd-Ecad). Three-dimensional human tissue constructs harboring either H-2Kd-Ecad-expressing or control II-4 cells (pBabe, H-2Kd-EcadDeltaC25) were cultured at an air-liquid interface for 8 days and transplanted to nude mice; tumor phenotype was analyzed 2 days and 2 and 4 weeks later. H-2Kd-Ecad-expressing tumors demonstrated a switch to a high-grade aggressive tumor phenotype characterized by poorly differentiated tumor cells that infiltrated throughout the stroma. This high-grade carcinoma revealed elevated cell proliferation in a random pattern, loss of keratin 1 and diffuse deposition of laminin 5 gamma2 chain. When II-4 cell variants were seeded into type I collagen gels as an in vitro assay for cell migration, we found that only E-cadherin-deficient cells detached, migrated as single cells and expressed N-cadherin. Function-blocking studies demonstrated that this migration was matrix metalloproteinase-dependent, as GM-6001 and TIMP-2, but not TIMP-1, could block migration. Gene expression profiles revealed that E-cadherin-deficient II-4 cells demonstrated increased expression of proteases and cell-cell and cell-matrix proteins. These findings showed that loss of E-cadherin-mediated adhesion plays a causal role in the transition from low- to high-grade squamous cell carcinomas and that the absence of E-cadherin is an important prognostic marker in the progression of this disease.

SASH1 inhibits cervical cancer cell proliferation and invasion by suppressing the FAK pathway.

PubMed

Chen, Hui; Wang, Dongliang; Liu, Yuling

2016-04-01

SAM and SH3 domain containing 1 (SASH1), a member of the SLY-family of signal adapter proteins, is a candidate tumor suppressor in several types of cancer. However, the role of SASH1 in cervical cancer remains to be elucidated. Therefore, in the present study, the role of SASH1 in cervical cancer and the underlying mechanism was investigated. Cell proliferation was detected by the MTT assay. Cell invasion was measured by Transwell assay. The mRNA expression levels of SASH1, matrix metalloproteinase (MMP)‑2 and MMP‑9 were determined by reverse transcription quantitative polymerase chain reaction. The protein expression levels of SASH1, MMP‑2, MMP‑9 and focal adhesion kinase (FAK) were determined by western blot analysis. The results demonstrated that SASH1 was downregulated in cervical cancer tissues and cell lines. Subsequently, a vector that overexpresses SASH1 was constructed. Overexpression of SASH1 was found to significantly inhibit cervical cancer cell proliferation and invasion, and also significantly reduce the expression of MMP‑2 and MMP‑9 in cancer cells. In addition, SASH1 modulated the FAK signaling pathway. Overexpression of SASH1 suppressed the expression of FAK in cancer cells. Taken together, the results suggested that SASH1 inhibits cervical cancer cell proliferation and invasion by suppressing the FAK pathway.

Invasion of Epithelial Cells and Proteolysis of Cellular Focal Adhesion Components by Distinct Types of Porphyromonas gingivalis Fimbriae

PubMed Central

Nakagawa, Ichiro; Inaba, Hiroaki; Yamamura, Taihei; Kato, Takahiro; Kawai, Shinji; Ooshima, Takashi; Amano, Atsuo

2006-01-01

Porphyromonas gingivalis fimbriae are classified into six types (types I to V and Ib) based on the fimA genes encoding FimA (a subunit of fimbriae), and they play a critical role in bacterial interactions with host tissues. In this study, we compared the efficiencies of P. gingivalis strains with distinct types of fimbriae for invasion of epithelial cells and for degradation of cellular focal adhesion components, paxillin, and focal adhesion kinase (FAK). Six representative strains with the different types of fimbriae were tested, and P. gingivalis with type II fimbriae (type II P. gingivalis) adhered to and invaded epithelial cells at significantly greater levels than the other strains. There were negligible differences in gingipain activities among the six strains; however, type II P. gingivalis apparently degraded intracellular paxillin in association with a loss of phosphorylation 30 min after infection. Degradation was blocked with cytochalasin D or in mutants with fimA disrupted. Paxillin was degraded by the mutant with Lys-gingipain disrupted, and this degradation was prevented by inhibition of Arg-gingipain activity by Nα-p-tosyl-l-lysine chloromethyl ketone. FAK was also degraded by type II P. gingivalis. Cellular focal adhesions with green fluorescent protein-paxillin macroaggregates were clearly destroyed, and this was associated with cellular morphological changes and microtubule disassembly. In an in vitro wound closure assay, type II P. gingivalis significantly inhibited cellular migration and proliferation compared to the cellular migration and proliferation observed with the other types. These results suggest that type II P. gingivalis efficiently invades epithelial cells and degrades focal adhesion components with Arg-gingipain, which results in cellular impairment during wound healing and periodontal tissue regeneration. PMID:16790749

The influence of nanostructured features on bacterial adhesion and bone cell functions on severely shot peened 316L stainless steel.

PubMed

Bagherifard, Sara; Hickey, Daniel J; de Luca, Alba C; Malheiro, Vera N; Markaki, Athina E; Guagliano, Mario; Webster, Thomas J

2015-12-01

Substrate grain structure and topography play major roles in mediating cell and bacteria activities. Severe plastic deformation techniques, known as efficient metal-forming and grain refining processes, provide the treated material with novel mechanical properties and can be adopted to modify nanoscale surface characteristics, possibly affecting interactions with the biological environment. This in vitro study evaluates the capability of severe shot peening, based on severe plastic deformation, to modulate the interactions of nanocrystallized metallic biomaterials with cells and bacteria. The treated 316L stainless steel surfaces were first investigated in terms of surface topography, grain size, hardness, wettability and residual stresses. The effects of the induced surface modifications were then separately studied in terms of cell morphology, adhesion and proliferation of primary human osteoblasts (bone forming cells) as well as the adhesion of multiple bacteria strains, specifically Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and ampicillin-resistant Escherichia coli. The results indicated a significant enhancement in surface work hardening and compressive residual stresses, maintenance of osteoblast adhesion and proliferation as well as a remarkable decrease in the adhesion and growth of gram-positive bacteria (S. aureus and S. epidermidis) compared to non-treated and conventionally shot peened samples. Impressively, the decrease in bacteria adhesion and growth was achieved without the use of antibiotics, for which bacteria can develop a resistance towards anyway. By slightly grinding the surface of severe shot peened samples to remove differences in nanoscale surface roughness, the effects of varying substrate grain size were separated from those of varying surface roughness. The expression of vinculin focal adhesions from osteoblasts was found to be singularly and inversely related to grain size, whereas the attachment of gram

Pretreatment of poly(l-lactide-co-glycolide) scaffolds with sodium hydroxide enhances osteoblastic differentiation and slows proliferation of mouse preosteoblast cells.

PubMed

Carpizo, Katherine H; Saran, Madeleine J; Huang, Weibiao; Ishida, Kenji; Roostaeian, Jason; Bischoff, David; Huang, Catherine K; Rudkin, George H; Yamaguchi, Dean T; Miller, Timothy A

2008-02-01

Surface topography is important in the creation of a scaffold for tissue engineering. Chemical etching of poly(l-lactide-co-glycolide) with sodium hydroxide has been shown to enhance adhesion and function of numerous cell types. The authors investigated the effects of sodium hydroxide pretreatment of three-dimensional poly(l-lactide-co-glycolide) scaffolds on the adhesion, differentiation, and proliferation of MC3T3-E1 murine preosteoblasts. MC3T3-E1 cells were seeded onto three-dimensional poly(l-lactide-co-glycolide) scaffolds with and without 1 M sodium hydroxide pretreatment. Cells were then cultured in osteogenic medium and harvested at varying time points for RNA extraction. Quantitative real-time reverse-transcriptase polymerase chain reaction was performed to measure mRNA expression of several osteogenic marker genes. In addition, cell numbers were determined at varying time points during the culture period. All experiments were performed in triplicate. Pretreatment of three-dimensional poly(l-lactide-co-glycolide) scaffolds with sodium hydroxide resulted in statistically significant up-regulation of mRNA expression of alkaline phosphatase, bone sialoprotein, osteocalcin, and vascular endothelial growth factor during the first 10 days of culture. Histologic analysis demonstrated a striking increase in mineralized cell matrix deposition in the sodium hydroxide-treated group. Cell number was statistically higher in the sodium hydroxide-treated group immediately after cell seeding, suggesting improved adhesion. During the first 24 hours of culture, cells grew faster in the control group than in the sodium hydroxide-treated group. Chemical etching of poly(l-lactide-co-glycolide) scaffolds with sodium hydroxide strongly influences the behavior of MC3T3-E1 preosteoblasts in vitro by enhancing adhesion and differentiation and slowing proliferation. Sodium hydroxide treatment may represent a simple and inexpensive way of improving scaffolds for use in bone tissue

Cell-cell and cell-extracellular matrix adhesions cooperate to organize actomyosin networks and maintain force transmission during dorsal closure.

PubMed

Goodwin, Katharine; Lostchuck, Emily E; Cramb, Kaitlyn M L; Zulueta-Coarasa, Teresa; Fernandez-Gonzalez, Rodrigo; Tanentzapf, Guy

2017-05-15

Tissue morphogenesis relies on the coordinated action of actin networks, cell-cell adhesions, and cell-extracellular matrix (ECM) adhesions. Such coordination can be achieved through cross-talk between cell-cell and cell-ECM adhesions. Drosophila dorsal closure (DC), a morphogenetic process in which an extraembryonic tissue called the amnioserosa contracts and ingresses to close a discontinuity in the dorsal epidermis of the embryo, requires both cell-cell and cell-ECM adhesions. However, whether the functions of these two types of adhesions are coordinated during DC is not known. Here we analyzed possible interdependence between cell-cell and cell-ECM adhesions during DC and its effect on the actomyosin network. We find that loss of cell-ECM adhesion results in aberrant distributions of cadherin-mediated adhesions and actin networks in the amnioserosa and subsequent disruption of myosin recruitment and dynamics. Moreover, loss of cell-cell adhesion caused up-regulation of cell-ECM adhesion, leading to reduced cell deformation and force transmission across amnioserosa cells. Our results show how interdependence between cell-cell and cell-ECM adhesions is important in regulating cell behaviors, force generation, and force transmission critical for tissue morphogenesis. © 2017 Goodwin, Lostchuck, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

High-content adhesion assay to address limited cell samples†

PubMed Central

Warrick, Jay W.; Young, Edmond W. K.; Schmuck, Eric G.; Saupe, Kurt W.

2013-01-01

Cell adhesion is a broad topic in cell biology that involves physical interactions between cells and other cells or the surrounding extracellular matrix, and is implicated in major research areas including cancer, development, tissue engineering, and regenerative medicine. While current methods have contributed significantly to our understanding of cell adhesion, these methods are unsuitable for tackling many biological questions requiring intermediate numbers of cells (102–105), including small animal biopsies, clinical samples, and rare cell isolates. To overcome this fundamental limitation, we developed a new assay to quantify the adhesion of ~102–103 cells at a time on engineered substrates, and examined the adhesion strength and population heterogeneity via distribution-based modeling. We validated the platform by testing adhesion strength of cancer cells from three different cancer types (breast, prostate, and multiple myeloma) on both IL-1β activated and non-activated endothelial monolayers, and observed significantly increased adhesion for each cancer cell type upon endothelial activation, while identifying and quantifying distinct subpopulations of cell-substrate interactions. We then applied the assay to characterize adhesion of primary bone marrow stromal cells to different cardiac fibroblast-derived matrix substrates to demonstrate the ability to study limited cell populations in the context of cardiac cell-based therapies. Overall, these results demonstrate the sensitivity and robustness of the assay as well as its ability to enable extraction of high content, functional data from limited and potentially rare primary samples. We anticipate this method will enable a new class of biological studies with potential impact in basic and translational research. PMID:23426645

The cancer cell adhesion resistome: mechanisms, targeting and translational approaches.

PubMed

Dickreuter, Ellen; Cordes, Nils

2017-06-27

Cell adhesion-mediated resistance limits the success of cancer therapies and is a great obstacle to overcome in the clinic. Since the 1990s, where it became clear that adhesion of tumor cells to the extracellular matrix is an important mediator of therapy resistance, a lot of work has been conducted to understand the fundamental underlying mechanisms and two paradigms were deduced: cell adhesion-mediated radioresistance (CAM-RR) and cell adhesion-mediated drug resistance (CAM-DR). Preclinical work has evidently demonstrated that targeting of integrins, adapter proteins and associated kinases comprising the cell adhesion resistome is a promising strategy to sensitize cancer cells to both radiotherapy and chemotherapy. Moreover, the cell adhesion resistome fundamentally contributes to adaptation mechanisms induced by radiochemotherapy as well as molecular drugs to secure a balanced homeostasis of cancer cells for survival and growth. Intriguingly, this phenomenon provides a basis for synthetic lethal targeted therapies simultaneously administered to standard radiochemotherapy. In this review, we summarize current knowledge about the cell adhesion resistome and highlight targeting strategies to override CAM-RR and CAM-DR.

Role of YAP/TAZ in cell-matrix adhesion-mediated signalling and mechanotransduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dupont, Sirio, E-mail: sirio.dupont@unipd.it

2016-04-10

Signalling from the extracellular matrix (ECM) is a fundamental cellular input that sustains proliferation, opposes cell death and regulates differentiation. Through integrins, cells perceive both the chemical composition and physical properties of the ECM. In particular, cell behaviour is profoundly influenced by the mechanical elasticity or stiffness of the ECM, which regulates the ability of cells to develop forces through their contractile actomyosin cytoskeleton and to mature focal adhesions. This mechanosensing ability affects fundamental cellular functions, such that alterations of ECM stiffness is nowadays considered not a simple consequence of pathology, but a causative input driving aberrant cell behaviours. Wemore » here discuss recent advances on how mechanical signals intersect nuclear transcription and in particular the activity of YAP/TAZ transcriptional coactivators, known downstream transducers of the Hippo pathway and important effectors of ECM mechanical cues.« less

The state diagram for cell adhesion under flow: leukocyte rolling and firm adhesion.

PubMed

Chang, K C; Tees, D F; Hammer, D A

2000-10-10

Leukocyte adhesion under flow in the microvasculature is mediated by binding between cell surface receptors and complementary ligands expressed on the surface of the endothelium. Leukocytes adhere to endothelium in a two-step mechanism: rolling (primarily mediated by selectins) followed by firm adhesion (primarily mediated by integrins). Using a computational method called "Adhesive Dynamics," we have simulated the adhesion of a cell to a surface in flow, and elucidated the relationship between receptor-ligand functional properties and the dynamics of adhesion. We express this relationship in a state diagram, a one-to-one map between the biophysical properties of adhesion molecules and various adhesive behaviors. Behaviors that are observed in simulations include firm adhesion, transient adhesion (rolling), and no adhesion. We varied the dissociative properties, association rate, bond elasticity, and shear rate and found that the unstressed dissociation rate, k(r)(o), and the bond interaction length, gamma, are the most important molecular properties controlling the dynamics of adhesion. Experimental k(r)(o) and gamma values from the literature for molecules that are known to mediate rolling adhesion fall within the rolling region of the state diagram. We explain why L-selectin-mediated rolling, which has faster k(r)(o) than other selectins, is accompanied by a smaller value for gamma. We also show how changes in association rate, shear rate, and bond elasticity alter the dynamics of adhesion. The state diagram (which must be mapped for each receptor-ligand system) presents a concise and comprehensive means of understanding the relationship between bond functional properties and the dynamics of adhesion mediated by receptor-ligand bonds.

Distinct Effects of RGD-glycoproteins on Integrin-Mediated Adhesion and Osteogenic Differentiation of Human Mesenchymal Stem Cells

PubMed Central

Schwab, Elisabeth H.; Halbig, Maria; Glenske, Kristina; Wagner, Alena-Svenja; Wenisch, Sabine; Cavalcanti-Adam, Elisabetta A.

2013-01-01

The detailed interactions of mesenchymal stem cells (MSCs) with their extracellular matrix (ECM) and the resulting effects on MSC differentiation are still largely unknown. Integrins are the main mediators of cell-ECM interaction. In this study, we investigated the adhesion of human MSCs to fibronectin, vitronectin and osteopontin, three ECM glycoproteins which contain an integrin-binding sequence, the RGD motif. We then assayed MSCs for their osteogenic commitment in the presence of the different ECM proteins. As early as 2 hours after seeding, human MSCs displayed increased adhesion when plated on fibronectin, whereas no significant difference was observed when adhering either to vitronectin or osteopontin. Over a 10-day observation period, cell proliferation was increased when cells were cultured on fibronectin and osteopontin, albeit after 5 days in culture. The adhesive role of fibronectin was further confirmed by measurements of cell area, which was significantly increased on this type of substrate. However, integrin-mediated clusters, namely focal adhesions, were larger and more mature in MSCs adhering to vitronectin and osteopontin. Adhesion to fibronectin induced elevated expression of α5-integrin, which was further upregulated under osteogenic conditions also for vitronectin and osteopontin. In contrast, during osteogenic differentiation the expression level of β3-integrin was decreased in MSCs adhering to the different ECM proteins. When MSCs were cultured under osteogenic conditions, their commitment to the osteoblast lineage and their ability to form a mineralized matrix in vitro was increased in presence of fibronectin and osteopontin. Taken together these results indicate a distinct role of ECM proteins in regulating cell adhesion, lineage commitment and phenotype of MSCs, which is due to the modulation of the expression of specific integrin subunits during growth or osteogenic differentiation. PMID:24324361

Distinct effects of RGD-glycoproteins on Integrin-mediated adhesion and osteogenic differentiation of human mesenchymal stem cells.

PubMed

Schwab, Elisabeth H; Halbig, Maria; Glenske, Kristina; Wagner, Alena-Svenja; Wenisch, Sabine; Cavalcanti-Adam, Elisabetta A

2013-01-01

The detailed interactions of mesenchymal stem cells (MSCs) with their extracellular matrix (ECM) and the resulting effects on MSC differentiation are still largely unknown. Integrins are the main mediators of cell-ECM interaction. In this study, we investigated the adhesion of human MSCs to fibronectin, vitronectin and osteopontin, three ECM glycoproteins which contain an integrin-binding sequence, the RGD motif. We then assayed MSCs for their osteogenic commitment in the presence of the different ECM proteins. As early as 2 hours after seeding, human MSCs displayed increased adhesion when plated on fibronectin, whereas no significant difference was observed when adhering either to vitronectin or osteopontin. Over a 10-day observation period, cell proliferation was increased when cells were cultured on fibronectin and osteopontin, albeit after 5 days in culture. The adhesive role of fibronectin was further confirmed by measurements of cell area, which was significantly increased on this type of substrate. However, integrin-mediated clusters, namely focal adhesions, were larger and more mature in MSCs adhering to vitronectin and osteopontin. Adhesion to fibronectin induced elevated expression of α₅-integrin, which was further upregulated under osteogenic conditions also for vitronectin and osteopontin. In contrast, during osteogenic differentiation the expression level of β₃-integrin was decreased in MSCs adhering to the different ECM proteins. When MSCs were cultured under osteogenic conditions, their commitment to the osteoblast lineage and their ability to form a mineralized matrix in vitro was increased in presence of fibronectin and osteopontin. Taken together these results indicate a distinct role of ECM proteins in regulating cell adhesion, lineage commitment and phenotype of MSCs, which is due to the modulation of the expression of specific integrin subunits during growth or osteogenic differentiation.

Selective Cell Adhesion and Biosensing Applications of Bio-Active Block Copolymers Prepared by CuAAC/Thiol-ene Double Click Reactions.

PubMed

Oyman Eyrilmez, Gizem; Doran, Sean; Murtezi, Eljesa; Demir, Bilal; Odaci Demirkol, Dilek; Coskunol, Hakan; Timur, Suna; Yagci, Yusuf

2015-09-01

N-Acetyl-l-cysteine (NAC)-capped poly(methyl methacrylate)-b-polycaprolactone block copolymer (PMMA-b-PCL-NAC) was prepared using the previously described one-pot photoinduced sequential CuAAC/thiol-ene double click procedure. PMMA-b-PCL-NAC had previously shown good applicability as a matrix for cell adhesion of cells from the Vero cell line (African green monkey kidney epithelial). Here, in this work, PMMA-b-PCL-NAC served as an excellent immobilization matrix for biomolecule conjugation. Covalent binding of RGD (R: arginine, G: glycine, and D: aspartic acid) peptide sequence onto the PMMA-b-PCL-NAC-coated surface was performed via EDC chemistry. RGD-modified PMMA-b-PCL-NAC (PMMA-b-PCL-NAC-RGD) as a non-toxic cell proliferation platform was used for selective "integrin αvβ3-mediated cell adhesion and biosensing studies. Both optical and electrochemical techniques were used to monitor the adhesion differences between "integrin αvβ3" receptor positive and negative cell lines on to the designed biofunctional surfaces. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rac-WAVE-mediated actin reorganization is required for organization and maintenance of cell-cell adhesion.

PubMed

Yamazaki, Daisuke; Oikawa, Tsukasa; Takenawa, Tadaomi

2007-01-01

During cadherin-dependent cell-cell adhesion, the actin cytoskeleton undergoes dynamic reorganization in epithelial cells. Rho-family small GTPases, which regulate actin dynamics, play pivotal roles in cadherin-dependent cell-cell adhesion; however, the precise molecular mechanisms that underlie cell-cell adhesion formation remain unclear. Here we show that Wiskott-Aldrich syndrome protein family verprolin-homologous protein (WAVE)-mediated reorganization of actin, downstream of Rac plays an important role in normal development of cadherin-dependent cell-cell adhesions in MDCK cells. Rac-induced development of cadherin-dependent adhesions required WAVE2-dependent actin reorganization. The process of cell-cell adhesion is divided into three steps: formation of new cell-cell contacts, stabilization of these new contacts and junction maturation. WAVE1 and WAVE2 were expressed in MDCK cells. The functions of WAVE1 and WAVE2 were redundant in this system but WAVE2 appeared to play a more significant role. During the first step, WAVE2-dependent lamellipodial protrusions facilitated formation of cell-cell contacts. During the second step, WAVE2 recruited actin filaments to new cell-cell contacts and stabilized newly formed cadherin clusters. During the third step, WAVE2-dependent actin reorganization was required for organization and maintenance of mature cell-cell adhesions. Thus, Rac-WAVE-dependent actin reorganization is not only involved in formation of cell-cell adhesions but is also required for their maintenance.

Aggregatibacter actinomycetemcomitans regulates the expression of integrins and reduces cell adhesion via integrin α5 in human gingival epithelial cells.

PubMed

Kochi, Shinsuke; Yamashiro, Keisuke; Hongo, Shoichi; Yamamoto, Tadashi; Ugawa, Yuki; Shimoe, Masayuki; Kawamura, Mari; Hirata-Yoshihara, Chiaki; Ideguchi, Hidetaka; Maeda, Hiroshi; Takashiba, Shogo

2017-12-01

Gingival epithelial cells form a physiological barrier against bacterial invasion. Excessive bacterial invasion destroys the attachment between the tooth surface and the epithelium, resulting in periodontitis. Integrins play a significant role in cell attachment; therefore, we hypothesized that bacterial infection might decrease the expressions of these integrins in gingival epithelial cells, resulting in reduced cell adhesion. Immortalized human gingival epithelial cells were co-cultured with Aggregatibacter actinomycetemcomitans Y4 (Aa Y4), and the gene expression levels of IL-8, proliferating cell nuclear antigen (PCNA), and integrins (α2, α3, α5, β4, and β6) were measured using quantitative reverse transcription polymerase chain reaction. Expression of PCNA and integrins, except integrin α5, was significantly downregulated, while expression of IL-8 and integrin α5 was significantly upregulated in the cells co-cultured with Aa Y4. The number of adherent cells significantly decreased when co-cultured with Aa Y4, as determined using cell adhesion assays. In the cells co-cultured with Aa Y4 and an integrin α5 neutralizing antibody, there was no effect on the expression of IL-8 and PCNA, while the expressions of integrins α2, α3, β4, and β6, and the number of adherent cells did not decrease. The number of invading bacteria in the cells was reduced in the presence of the antibody and increased in the presence of TLR2/4 inhibitor. Therefore, integrin α5 might be involved in Aa Y4 invasion into gingival epithelial cells, and the resulting signal transduction cascade reduces cell adhesion by decreasing the expression of integrins, while the TLR2/4 signaling cascade regulates IL-8 expression.

Myocilin Regulates Cell Proliferation and Survival*

PubMed Central

Joe, Myung Kuk; Kwon, Heung Sun; Cojocaru, Radu; Tomarev, Stanislav I.

2014-01-01

Myocilin, a causative gene for open angle glaucoma, encodes a secreted glycoprotein with poorly understood functions. To gain insight into its functions, we produced a stably transfected HEK293 cell line expressing myocilin under an inducible promoter and compared gene expression profiles between myocilin-expressing and vector control cell lines by a microarray analysis. A significant fraction of differentially expressed genes in myocilin-expressing cells was associated with cell growth and cell death, suggesting that myocilin may have a role in the regulation of cell growth and survival. Increased proliferation of myocilin-expressing cells was demonstrated by the WST-1 proliferation assay, direct cell counting, and immunostaining with antibodies against Ki-67, a cellular proliferation marker. Myocilin-containing conditioned medium also increased proliferation of unmodified HEK293 cells. Myocilin-expressing cells were more resistant to serum starvation-induced apoptosis than control cells. TUNEL-positive apoptotic cells were dramatically decreased, and two apoptotic marker proteins, cleaved caspase 7 and cleaved poly(ADP-ribose) polymerase, were significantly reduced in myocilin-expressing cells as compared with control cells under apoptotic conditions. In addition, myocilin-deficient mesenchymal stem cells exhibited reduced proliferation and enhanced susceptibility to serum starvation-induced apoptosis as compared with wild-type mesenchymal stem cells. Phosphorylation of ERK1/2 and its upstream kinases, c-Raf and MEK, was increased in myocilin-expressing cells compared with control cells. Elevated phosphorylation of ERK1/2 was also observed in the trabecular meshwork of transgenic mice expressing 6-fold higher levels of myocilin when compared with their wild-type littermates. These results suggest that myocilin promotes cell proliferation and resistance to apoptosis via the ERK1/2 MAPK signaling pathway. PMID:24563482

Cell Adhesion Minimization by a Novel Mesh Culture Method Mechanically Directs Trophoblast Differentiation and Self-Assembly Organization of Human Pluripotent Stem Cells.

PubMed

Okeyo, Kennedy Omondi; Kurosawa, Osamu; Yamazaki, Satoshi; Oana, Hidehiro; Kotera, Hidetoshi; Nakauchi, Hiromitsu; Washizu, Masao

2015-10-01

Mechanical methods for inducing differentiation and directing lineage specification will be instrumental in the application of pluripotent stem cells. Here, we demonstrate that minimization of cell-substrate adhesion can initiate and direct the differentiation of human pluripotent stem cells (hiPSCs) into cyst-forming trophoblast lineage cells (TLCs) without stimulation with cytokines or small molecules. To precisely control cell-substrate adhesion area, we developed a novel culture method where cells are cultured on microstructured mesh sheets suspended in a culture medium such that cells on mesh are completely out of contact with the culture dish. We used microfabricated mesh sheets that consisted of open meshes (100∼200 μm in pitch) with narrow mesh strands (3-5 μm in width) to provide support for initial cell attachment and growth. We demonstrate that minimization of cell adhesion area achieved by this culture method can trigger a sequence of morphogenetic transformations that begin with individual hiPSCs attached on the mesh strands proliferating to form cell sheets by self-assembly organization and ultimately differentiating after 10-15 days of mesh culture to generate spherical cysts that secreted human chorionic gonadotropin (hCG) hormone and expressed caudal-related homeobox 2 factor (CDX2), a specific marker of trophoblast lineage. Thus, this study demonstrates a simple and direct mechanical approach to induce trophoblast differentiation and generate cysts for application in the study of early human embryogenesis and drug development and screening.

Effect of Clinically Relevant CAD/CAM Zirconia Polishing on Gingival Fibroblast Proliferation and Focal Adhesions

PubMed Central

Fischer, Nicholas G.; Wong, Jeffrey; Cerutis, D. Roselyn

2017-01-01

Mucosal seal formation around dental abutments is critical to the successful integration of dental implants into the human oral cavity. No information exists for how clinically relevant polishing procedures for computer-aided design and computer-aided manufactured (CAD/CAM) zirconia abutments affects cellular responses important to mucosal seal formation. CAD/CAM zirconia was divided into four groups for clinically relevant polishing utilizing commercial polishing heads: control, coarse, coarse plus medium, and coarse plus medium plus fine. Surfaces were analyzed with scanning electron microscopy (SEM), atomic force microscopy (AFM), and optical profilometry (OP). Subsequently, human gingival fibroblasts (HGFs) were seeded onto the zirconia surfaces. Proliferation was measured via a quantitative SEM technique and focal adhesion kinase (FAK) phosphorylation status was measured by an enzyme-linked immunosorbent assay (ELISA). Results showed an increase in proliferation on all polished surfaces as compared to the control. Phosphorylation of FAK at tyrosine 397 (Y397) was up-modulated on the control surfaces. The associated cell adaptation is discussed. In all cases, FAK phosphorylation was greater at 24 h than 48 h. These results suggest that clinicians should be mindful of the effects of abutment polishing methodology, as this may have an impact on early mucosal seal formation. PMID:29186907

Cell adhesion molecules, the extracellular matrix and oral squamous carcinoma.

PubMed

Lyons, A J; Jones, J

2007-08-01

Carcinomas are characterized by invasion of malignant cells into the underlying connective tissue and migration of malignant cells to form metastases at distant sites. These processes require alterations in cell-cell and cell-extracellular matrix interactions. As cell adhesion molecules play a role in cell-cell and cell-extracellular matrix adhesion and interactions they are involved in the process of tumour invasion and metastases. In epithelial tissues, receptors of the integrin family mediate adhesion to the adjacent matrix whereas cadherins largely mediate intercellular adhesion. These and other cell adhesion molecules such as intercellular adhesion molecule-1, CD44, dystroglycans and selectins, are involved and undergo changes in carcinomas, which provide possible targets for anti-cancer drug treatments. In the extracellular matrix that is associated with tumours, laminin 5, oncofetal fibronectin and tenascin C appear. The degree of expression of some of these moieties indicates prognosis in oral cancer and offer targets for antibody-directed radiotherapy. Metalloproteases which degrade the extracellular matrix are increased in carcinomas, and their activity is necessary for tumour angiogenesis and consequent invasion and metastases. Metalloprotease inhibitors have begun to produce decreases in mortality in clinical trials. This report provides a brief overview of our current understanding of cell adhesion molecules, the extracellular matrix, tumour invasion and metastasis.

Estradiol, tamoxifen and ICI 182,780 alter alpha3 and beta1 integrin expression and laminin-1 adhesion in oral squamous cell carcinoma cell cultures.

PubMed

Nelson, Katja; Helmstaedter, Victor; Moreau, Cynthia; Lage, Hermann

2008-01-01

Adhesion molecules such as integrins and extracellular matrix proteins like laminins have been identified to play an important role in cell proliferation, migration and invasion by regulating cell-extracellular matrix interaction in various cancers including oral squamous cell carcinoma (OSCC). In this study, the effect of estradiol (E2), and the E2 antagonists tamoxifen (TAM) and ICI 182,780 (ICI) on the expression of integrins and adhesion to laminin-1 in different OSCC in vitro models was analyzed. TAM and ICI inhibited growth in all OSCC cell lines. Dependent on estrogen receptor (ER) status E2 displayed a significant influence on growth after long-term administration. ICI reduced laminin-1 adhesion in all cell lines. beta1 Integrin transcription is reduced with TAM and E2 and alpha3 cell surface expression with TAM. This study shows that OSCC is estrogen and SERM sensitive and that these compounds can modulate cell-matrix interaction in part by modulating integrin expression and translation. The investigation also confirms that growth is significantly influenced by these adjuvant therapeutics. These data suggest that a greater understanding of basic biology and mechanisms of the ER and its ligands in oral squamous cells is needed to elucidate the use of specific pharmacological agents as therapeutics of anti-tumorigenic pathways.

Colon cancer-associated B2 Escherichia coli colonize gut mucosa and promote cell proliferation

PubMed Central

Raisch, Jennifer; Buc, Emmanuel; Bonnet, Mathilde; Sauvanet, Pierre; Vazeille, Emilie; de Vallée, Amélie; Déchelotte, Pierre; Darcha, Claude; Pezet, Denis; Bonnet, Richard; Bringer, Marie-Agnès; Darfeuille-Michaud, Arlette

2014-01-01

AIM: To provide further insight into the characterization of mucosa-associated Escherichia coli (E. coli) isolated from the colonic mucosa of cancer patients. METHODS: Phylogroups and the presence of cyclomodulin-encoding genes of mucosa-associated E. coli from colon cancer and diverticulosis specimens were determined by PCR. Adhesion and invasion experiments were performed with I-407 intestinal epithelial cells using gentamicin protection assay. Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) expression in T84 intestinal epithelial cells was measured by enzyme-linked immunosorbent assay and by Western Blot. Gut colonization, inflammation and pro-carcinogenic potential were assessed in a chronic infection model using CEABAC10 transgenic mice. Cell proliferation was analyzed by real-time mRNA quantification of PCNA and immunohistochemistry staining of Ki67. RESULTS: Analysis of mucosa-associated E. coli from colon cancer and diverticulosis specimens showed that whatever the origin of the E. coli strains, 86% of cyclomodulin-positive E. coli belonged to B2 phylogroup and most harbored polyketide synthase (pks) island, which encodes colibactin, and/or cytotoxic necrotizing factor (cnf) genes. In vitro assays using I-407 intestinal epithelial cells revealed that mucosa-associated B2 E. coli strains were poorly adherent and invasive. However, mucosa-associated B2 E. coli similarly to Crohn’s disease-associated E. coli are able to induce CEACAM6 expression in T84 intestinal epithelial cells. In addition, in vivo experiments using a chronic infection model of CEACAM6 expressing mice showed that B2 E. coli strain 11G5 isolated from colon cancer is able to highly persist in the gut, and to induce colon inflammation, epithelial damages and cell proliferation. CONCLUSION: In conclusion, these data bring new insights into the ability of E. coli isolated from patients with colon cancer to establish persistent colonization, exacerbate inflammation and

High aspect ratio silicon nanowires control fibroblast adhesion and cytoskeleton organization

NASA Astrophysics Data System (ADS)

Andolfi, Laura; Murello, Anna; Cassese, Damiano; Ban, Jelena; Dal Zilio, Simone; Lazzarino, Marco

2017-04-01

Cell-cell and cell-matrix interactions are essential to the survival and proliferation of most cells, and are responsible for triggering a wide range of biochemical pathways. More recently, the biomechanical role of those interactions was highlighted, showing, for instance, that adhesion forces are essential for cytoskeleton organization. Silicon nanowires (Si NWs) with their small size, high aspect ratio and anisotropic mechanical response represent a useful model to investigate the forces involved in the adhesion processes and their role in cellular development. In this work we explored and quantified, by single cell force spectroscopy (SCFS), the interaction of mouse embryonic fibroblasts with a flexible forest of Si NWs. We observed that the cell adhesion forces are comparable to those found on collagen and bare glass coverslip, analogously the membrane tether extraction forces are similar to that on collagen but stronger than that on bare flat glass. Cell survival did not depend significantly on the substrate, although a reduced proliferation after 36 h was observed. On the contrary both cell morphology and cytoskeleton organization revealed striking differences. The cell morphology on Si-NW was characterized by a large number of filopodia and a significant decrease of the cell mobility. The cytoskeleton organization was characterized by the absence of actin fibers, which were instead dominant on collagen and flat glass support. Such findings suggest that the mechanical properties of disordered Si NWs, and in particular their strong asymmetry, play a major role in the adhesion, morphology and cytoskeleton organization processes. Indeed, while adhesion measurements by SCFS provide out-of-plane forces values consistent with those measured on conventional substrates, weaker in-plane forces hinder proper cytoskeleton organization and migration processes.

High aspect ratio silicon nanowires control fibroblast adhesion and cytoskeleton organization.

PubMed

Andolfi, Laura; Murello, Anna; Cassese, Damiano; Ban, Jelena; Dal Zilio, Simone; Lazzarino, Marco

2017-04-18

Cell-cell and cell-matrix interactions are essential to the survival and proliferation of most cells, and are responsible for triggering a wide range of biochemical pathways. More recently, the biomechanical role of those interactions was highlighted, showing, for instance, that adhesion forces are essential for cytoskeleton organization. Silicon nanowires (Si NWs) with their small size, high aspect ratio and anisotropic mechanical response represent a useful model to investigate the forces involved in the adhesion processes and their role in cellular development. In this work we explored and quantified, by single cell force spectroscopy (SCFS), the interaction of mouse embryonic fibroblasts with a flexible forest of Si NWs. We observed that the cell adhesion forces are comparable to those found on collagen and bare glass coverslip, analogously the membrane tether extraction forces are similar to that on collagen but stronger than that on bare flat glass. Cell survival did not depend significantly on the substrate, although a reduced proliferation after 36 h was observed. On the contrary both cell morphology and cytoskeleton organization revealed striking differences. The cell morphology on Si-NW was characterized by a large number of filopodia and a significant decrease of the cell mobility. The cytoskeleton organization was characterized by the absence of actin fibers, which were instead dominant on collagen and flat glass support. Such findings suggest that the mechanical properties of disordered Si NWs, and in particular their strong asymmetry, play a major role in the adhesion, morphology and cytoskeleton organization processes. Indeed, while adhesion measurements by SCFS provide out-of-plane forces values consistent with those measured on conventional substrates, weaker in-plane forces hinder proper cytoskeleton organization and migration processes.

Hypergravity Stimulates the Extracellular Matrix/Integrin-Signaling Axis and Proliferation in Primary Osteoblasts

NASA Technical Reports Server (NTRS)

Parra, M.; Vercoutere, W.; Roden, C.; Banerjee, I.; Krauser, W.; Holton, E.; Searby, N.; Globus, R.; Almeida, E.

2003-01-01

We set out to determine the molecular mechanisms involved in the proliferative response of primary rat osteoblasts to mechanical stimulation using cell culture centrifugation as a model for hypergravity. We hypothesized that this proliferative response is mediated by specific integrin/Extracellular Matrix (ECM) interactions. To investigate this question we developed a cell culture centrifuge and an automated system that performs cell fixation during hypergravity loading. We generated expression vectors for various focal adhesion and cytoskeletal proteins fused to GFP or dsRed and visualized these structures in transfected (or infected) osteoblasts. The actin cytoskeleton was also visualized using rhodamine-phalloidin staining and Focal Adhesion Kinase (FAK) levels were assessed biochemically. We observed that a 24 hour exposure to 50-g stimulated proliferation compared to the 1-g control when cells were plated on fibronectin, collagen Type I , and collagen Type IV, but not on uncoated tissue culture plastic surfaces. This proliferative response was greatest for osteoblasts grown on fibronectin (2-fold increase over 1-g control) and collagen Type I (1.4 fold increase over 1-g control), suggesting that specific matrices and integrins are involved in the signaling pathways required for proliferation. Exposing osteoblasts grown on different matrices to 10-g or 25-g showed that effects on proliferation depended on both matrix type and loading level. We found that osteoblasts exposed to a short pulse of hypergravity during adhesion spread further and had more GFP-FAK containing focal adhesions compared to their 1-g controls. While overall levels of FAK did not change, more FAK was in the active (phosphorylated) form under hypergravity than in the 1-g controls. Cytoskeletal F-actin organization into filaments was also more prominent after brief exposures to hypergravity during the first five minutes of adhesion. These results suggest that specific integrins sense

MAPs/bFGF-PLGA microsphere composite-coated titanium surfaces promote increased adhesion and proliferation of fibroblasts.

PubMed

Wang, Zhongshan; Wu, Guofeng; Bai, Shizhu; Feng, Zhihong; Dong, Yan; Zhou, Jian; Qin, Haiyan; Zhao, Yimin

2014-06-01

Infection and epithelial downgrowth are two major problems with maxillofacial transcutaneous implants, and both are mainly due to lack of stable closure of soft tissues at transcutaneous sites. Fibroblasts have been shown to play a key role in the formation of biological seals. In this work, titanium (Ti) model surfaces were coated with mussel adhesive proteins (MAPs) utilizing its unique adhesion ability on diverse inorganic and organic surfaces in wet environments. Prepared basic fibroblast growth factor (bFGF)-poly(lactic-co-glycolic acid) (PLGA) microspheres can be easily synthesized and combined onto MAPs-coated Ti surfaces, due to the negative surface charges of microspheres in aqueous solution, which is in contrast to the positive charges of MAPs. Titanium model surfaces were divided into three groups. Group A: MAPs/bFGF-PLGA microspheres composite-coated Ti surfaces. Group B: MAPs-coated Ti surfaces. Group C: uncoated Ti surfaces. The effects of coated Ti surfaces on adhesion of fibroblasts, cytoskeletal organization, proliferation, and extracellular matrix (ECM)-related gene expressions were examined. The results revealed increased adhesion (P < 0.05), enhanced actin cytoskeletal organization, and up-regulated ECM-related gene expressions in groups A and B compared with group C. Increased proliferation of fibroblasts during five days of incubation was observed in group A compared with groups B and C (P < 0.05). Collectively, the results from this in vitro study demonstrated that MAPs/bFGF-PLGA microspheres composite-coated Ti surfaces had the ability to increase fibroblast functionality. In addition, MAPs/bFGF-PLGA microsphere composite-coated Ti surfaces should be studied further as a method of promoting formation of stable biological seals around transcutaneous sites.

Rapid and Localized Mechanical Stimulation and Adhesion Assay: TRPM7 Involvement in Calcium Signaling and Cell Adhesion

PubMed Central

Nishitani, Wagner Shin; Alencar, Adriano Mesquita; Wang, Yingxiao

2015-01-01

A cell mechanical stimulation equipment, based on cell substrate deformation, and a more sensitive method for measuring adhesion of cells were developed. A probe, precisely positioned close to the cell, was capable of a vertical localized mechanical stimulation with a temporal frequency of 207 Hz, and strain magnitude of 50%. This setup was characterized and used to probe the response of Human Umbilical Endothelial Vein Cells (HUVECs) in terms of calcium signaling. The intracellular calcium ion concentration was measured by the genetically encoded Cameleon biosensor, with the Transient Receptor Potential cation channel, subfamily M, member 7 (TRPM7) expression inhibited. As TRPM7 expression also regulates adhesion, a relatively simple method for measuring adhesion of cells was also developed, tested and used to study the effect of adhesion alone. Three adhesion conditions of HUVECs on polyacrylamide gel dishes were compared. In the first condition, the substrate is fully treated with Sulfo-SANPAH crosslinking and fibronectin. The other two conditions had increasingly reduced adhesion: partially treated (only coated with fibronectin, with no use of Sulfo-SANPAH, at 5% of the normal amount) and non-treated polyacrylamide gels. The cells showed adhesion and calcium response to the mechanical stimulation correlated to the degree of gel treatment: highest for fully treated gels and lowest for non-treated ones. TRPM7 inhibition by siRNA on HUVECs caused an increase in adhesion relative to control (no siRNA treatment) and non-targeting siRNA, but a decrease to 80% of calcium response relative to non-targeting siRNA which confirms the important role of TRPM7 in mechanotransduction despite the increase in adhesion. PMID:25946314

Inhibition of PTP1B disrupts cell–cell adhesion and induces anoikis in breast epithelial cells

PubMed Central

Hilmarsdottir, Bylgja; Briem, Eirikur; Halldorsson, Skarphedinn; Kricker, Jennifer; Ingthorsson, Sævar; Gustafsdottir, Sigrun; Mælandsmo, Gunhild M; Magnusson, Magnus K; Gudjonsson, Thorarinn

2017-01-01

Protein tyrosine phosphatase 1B (PTP1B) is a well-known inhibitor of insulin signaling pathways and inhibitors against PTP1B are being developed as promising drug candidates for treatment of obesity. PTP1B has also been linked to breast cancer both as a tumor suppressor and as an oncogene. Furthermore, PTP1B has been shown to be a regulator of cell adhesion and migration in normal and cancer cells. In this study, we analyzed the PTP1B expression in normal breast tissue, primary breast cells and the breast epithelial cell line D492. In normal breast tissue and primary breast cells, PTP1B is widely expressed in both epithelial and stromal cells, with highest expression in myoepithelial cells and fibroblasts. PTP1B is widely expressed in branching structures generated by D492 when cultured in 3D reconstituted basement membrane (3D rBM). Inhibition of PTP1B in D492 and another mammary epithelial cell line HMLE resulted in reduced cell proliferation and induction of anoikis. These changes were seen when cells were cultured both in monolayer and in 3D rBM. PTP1B inhibition affected cell attachment, expression of cell adhesion proteins and actin polymerization. Moreover, epithelial to mesenchymal transition (EMT) sensitized cells to PTP1B inhibition. A mesenchymal sublines of D492 and HMLE (D492M and HMLEmes) were more sensitive to PTP1B inhibition than D492 and HMLE. Reversion of D492M to an epithelial state using miR-200c-141 restored resistance to detachment induced by PTP1B inhibition. In conclusion, we have shown that PTP1B is widely expressed in the human breast gland with highest expression in myoepithelial cells and fibroblasts. Inhibition of PTP1B in D492 and HMLE affects cell–cell adhesion and induces anoikis-like effects. Finally, cells with an EMT phenotype are more sensitive to PTP1B inhibitors making PTP1B a potential candidate for further studies as a target for drug development in cancer involving the EMT phenotype. PMID:28492548

Cell adhesion to borate glasses by colloidal probe microscopy.

PubMed

Wiederhorn, Sheldon M; Chae, Young-Hun; Simon, Carl G; Cahn, Jackson; Deng, Yan; Day, Delbert

2011-05-01

The adhesion of osteoblast-like cells to silicate and borate glasses was measured in cell growth medium using colloidal probe microscopy. The probes consisted of silicate and borate glass spheres, 25-50 μm in diameter, attached to atomic force microscope cantilevers. Variables of the study included glass composition and time of contact of the cell to the glasses. Increasing the time of contact from 15 to 900 s increased the force of adhesion. The data could be plotted linearly on a log-log plot of adhesive force versus time. Of the seven glasses tested, five had slopes close to 0.5, suggesting a square root dependence of the adhesive force on the contact time. Such behavior can be interpreted as a diffusion limited process occurring during the early stages of cell attachment. We suggest that the rate limiting step in the adhesion process is the diffusion of integrins resident in the cell membrane to the area of cell attachment. Data presented in this paper support the hypothesis of Hench et al. that strong adhesion depends on the formation of a calcium phosphate reaction layer on the surfaces of the glass. Glasses that did not form a calcium phosphate layer exhibited a weaker adhesive force relative to those glasses that did form a calcium phosphate layer. Published by Elsevier Ltd.

A multi-targeted natural flavonoid myricetin impedes abnormal glioblastoma cell motility and invasiveness via suppressing lamellipodia and focal adhesions formation.

PubMed

Zhao, Hua-Fu; Wang, Gang; Wu, Chang-Peng; Zhou, Xiu-Ming; Wang, Jing; Chen, Zhong-Ping; To, Shing-Shun Tony; Li, Wei-Ping

2018-06-10

Glioblastoma multiforme (GBM) is the most aggressive and malignant primary brain tumor characterized by rapid growth and extensive infiltration to neighboring normal brain parenchyma, which contribute to tumor recurrence and poor prognosis. Myricetin is a natural flavonoid with potent anti-oxidant, anti-inflammatory and anti-cancer activities, which may serve as a potential and harmless agent for GBM treatment. To investigate the anti-glioblastoma effects of myricetin, GBM cells were treated with myricetin alone or in combination with temozolomide. Its effects on GBM cell motility and cytoskeletal structures including lamellipodia, focal adhesions and membrane ruffles were also evaluated. We showed that myricetin alone inhibited glioblastoma U-87 MG cell proliferation, migration and invasion, whereas combination of myricetin and temozolomide did not exhibit any synergistic effect. The inhibitory effect on GBM cell proliferation is independent of PTEN status. Moreover, myricetin showed less cytotoxicity to normal astrocytes than GBM cells. Formation of lamellipodia, focal adhesions, membrane ruffles and vasculogenic mimicry were blocked by myricetin though suppressing ROCK2, paxillin and cortactin phosphorylation. In addition, myricetin could bind to a series of kinases and scaffold proteins including PI3K catalytic isoforms (p110α, p110β and p110δ), PDK1, JNK, c-Jun, ROCK2, paxillin, vinculin and VE-cadherin, leading to inactivation of PI3K/Akt and JNK signaling. In conclusion, myricetin is a multi-targeted drug that has potent anti-migratory and anti-invasive effects on GBM cells via suppressing formation of lamellipodia and focal adhesions, suggesting that it may serve as an alternative option for GBM treatment. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Increasing α7β1-integrin promotes muscle cell proliferation, adhesion, and resistance to apoptosis without changing gene expression

PubMed Central

Liu, Jianming; Burkin, Dean J.; Kaufman, Stephen J.

2008-01-01

The dystrophin-glycoprotein complex maintains the integrity of skeletal muscle by associating laminin in the extracellular matrix with the actin cytoskeleton. Several human muscular dystrophies arise from defects in the components of this complex. The α7β1-integrin also binds laminin and links the extracellular matrix with the cytoskeleton. Enhancement of α7-integrin levels alleviates pathology in mdx/utrn−/− mice, a model of Duchenne muscular dystrophy, and thus the integrin may functionally compensate for the absence of dystrophin. To test whether increasing α7-integrin levels affects transcription and cellular functions, we generated α7-integrin-inducible C2C12 cells and transgenic mice that overexpress the integrin in skeletal muscle. C2C12 myoblasts with elevated levels of integrin exhibited increased adhesion to laminin, faster proliferation when serum was limited, resistance to staurosporine-induced apoptosis, and normal differentiation. Transgenic expression of eightfold more integrin in skeletal muscle did not result in notable toxic effects in vivo. Moreover, high levels of α7-integrin in both myoblasts and in skeletal muscle did not disrupt global gene expression profiles. Thus increasing integrin levels can compensate for defects in the extracellular matrix and cytoskeleton linkage caused by compromises in the dystrophin-glycoprotein complex without triggering apparent overt negative side effects. These results support the use of integrin enhancement as a therapy for muscular dystrophy. PMID:18045857

Screening and characterization of a Annenix A2 binding aptamer that inhibits the proliferation of myeloma cells.

PubMed

Zhou, Weihua; Zhang, Yibin; Zeng, Yayue; Peng, Minyuan; Li, Hui; Sun, Shuming; Ma, Bianying; Wang, Yanpeng; Ye, Mao; Liu, Jing

2018-06-12

Multiple myeloma (MM) is a malignant plasma cell disease and is considered incurable. Annexin A2 (ANXA2) is closely related to the proliferation and adhesion of MM. Using protein-SELEX, we performed a screen for aptamers that bind GST-ANXA2 from a library, and GST protein was used for negative selection. The enrichment of the ssDNA pool was monitored by filter-binding assay during selection. After nine rounds of screening and high-throughput sequencing, we obtained six candidate aptamers that bind to the ANXA2 protein. The affinities of the candidate aptamers for ANXA2 were determined by ELONA. Binding of aptamer wh6 to the ANXA2 protein and to the MM cell was verified by aptamer pulldown experiment and flow cytometry, respectively. Aptamer wh6 binds the ANXA2 protein with good stability and has a dissociation constant in the nanomolar range. The binding specificity of aptamer wh6 was confirmed in vivo in nude mouse xenografts with MM cells and with MM bone marrow aspirates. Furthermore, aptamer wh6 can block MM cell adhesion to ANXA2 and block the proliferation of MM cells induced by ANXA2. In summary, wh6 can be considered a promising candidate tool for MM diagnosis and treatment. Copyright © 2018 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

A bioactive triphasic ceramic-coated hydroxyapatite promotes proliferation and osteogenic differentiation of human bone marrow stromal cells.

PubMed

Nair, Manitha B; Bernhardt, Anne; Lode, Anja; Heinemann, Christiane; Thieme, Sebastian; Hanke, Thomas; Varma, Harikrishna; Gelinsky, Michael; John, Annie

2009-08-01

Hydroxyapatite (HA) ceramics are widely used as bone graft substitutes because of their biocompatibility and osteoconductivity. However, to enhance the success of therapeutic application, many efforts are undertaken to improve the bioactivity of HA. We have developed a triphasic, silica-containing ceramic-coated hydroxyapatite (HASi) and evaluated its performance as a scaffold for cell-based tissue engineering applications. Human bone marrow stromal cells (hBMSCs) were seeded on both HASi and HA scaffolds and cultured with and without osteogenic supplements for a period of 4 weeks. Cellular responses were determined in vitro in terms of cell adhesion, viability, proliferation, and osteogenic differentiation, where both materials exhibited excellent cytocompatibility. Nevertheless, an enhanced rate of cell proliferation and higher levels of both alkaline phosphatase expression and activity were observed for cells cultured on HASi with osteogenic supplements. These findings indicate that the bioactivity of HA endowed with a silica-containing coating has definitely influenced the cellular activity, projecting HASi as a suitable candidate material for bone regenerative therapy.

Ox-LDL Promotes Migration and Adhesion of Bone Marrow-Derived Mesenchymal Stem Cells via Regulation of MCP-1 Expression

PubMed Central

Wang, Congrui; Wang, Huaibin; Lu, Ming; Li, Yonghai; Feng, Huigen; Yuan, Zhiqing

2013-01-01

Bone marrow-derived mesenchymal stem cells (bmMSCs) are the most important cell source for stem cell transplant therapy. The migration capacity of MSCs is one of the determinants of the efficiency of MSC-based transplant therapy. Our recent study has shown that low concentrations of oxidized low-density lipoprotein (ox-LDL) can stimulate proliferation of bmMSCs. In this study, we investigated the effects of ox-LDL on bmMSC migration and adhesion, as well as the related mechanisms. Our results show that transmigration rates of bmMSCs and cell-cell adhesion between bmMSCs and monocytes are significantly increased by treatments with ox-LDL in a dose- and time-dependent manner. Expressions of ICAM-1, PECAM-1, and VCAM-1 as well as the levels of intracellular Ca2+ are also markedly increased by ox-LDL in a dose-dependent manner. Cytoskeleton analysis shows that ox-LDL treatment benefits to spreading of bmMSCs and organization of F-actin fibers after being plated for 6 hours. More interestingly, treatments with ox-LDL also markedly increase expressions of LOX-1, MCP-1, and TGF-β; however, LOX-1 antibody and MCP-1 shRNA markedly inhibit ox-LDL-induced migration and adhesion of bmMSCs, which suggests that ox-LDL-induced bmMSC migration and adhesion are dependent on LOX-1 activation and MCP-1 expression. PMID:23956504

Desmoglein 3 regulates membrane trafficking of cadherins, an implication in cell-cell adhesion.

PubMed

Moftah, Hanan; Dias, Kasuni; Apu, Ehsanul Hoque; Liu, Li; Uttagomol, Jutamas; Bergmeier, Lesley; Kermorgant, Stephanie; Wan, Hong

2017-05-04

E-cadherin mediated cell-cell adhesion plays a critical role in epithelial cell polarization and morphogenesis. Our recent studies suggest that the desmosomal cadherin, desmoglein 3 (Dsg3) cross talks with E-cadherin and regulates its adhesive function in differentiating keratinocytes. However, the underlying mechanism remains not fully elucidated. Since E-cadherin trafficking has been recognized to be a central determinant in cell-cell adhesion and homeostasis we hypothesize that Dsg3 may play a role in regulating E-cadherin trafficking and hence the cell-cell adhesion. Here we investigated this hypothesis in cells with loss of Dsg3 function through RNAi mediated Dsg3 knockdown or the stable expression of the truncated mutant Dsg3ΔC. Our results showed that loss of Dsg3 resulted in compromised cell-cell adhesion and reduction of adherens junction and desmosome protein expression as well as the cortical F-actin formation. As a consequence, cells failed to polarize but instead displayed aberrant cell flattening. Furthermore, retardation of E-cadherin internalization and recycling was consistently observed in these cells during the process of calcium induced junction assembling. In contrast, enhanced cadherin endocytosis was detected in cells with overexpression of Dsg3 compared to control cells. Importantly, this altered cadherin trafficking was found to be coincided with the reduced expression and activity of Rab proteins, including Rab5, Rab7 and Rab11 which are known to be involved in E-cadherin trafficking. Taken together, our findings suggest that Dsg3 functions as a key in cell-cell adhesion through at least a mechanism of regulating E-cadherin membrane trafficking.

Desmoglein 3 regulates membrane trafficking of cadherins, an implication in cell-cell adhesion

PubMed Central

Moftah, Hanan; Dias, Kasuni; Apu, Ehsanul Hoque; Liu, Li; Uttagomol, Jutamas; Bergmeier, Lesley; Kermorgant, Stephanie; Wan, Hong

2017-01-01

ABSTRACT E-cadherin mediated cell-cell adhesion plays a critical role in epithelial cell polarization and morphogenesis. Our recent studies suggest that the desmosomal cadherin, desmoglein 3 (Dsg3) cross talks with E-cadherin and regulates its adhesive function in differentiating keratinocytes. However, the underlying mechanism remains not fully elucidated. Since E-cadherin trafficking has been recognized to be a central determinant in cell-cell adhesion and homeostasis we hypothesize that Dsg3 may play a role in regulating E-cadherin trafficking and hence the cell-cell adhesion. Here we investigated this hypothesis in cells with loss of Dsg3 function through RNAi mediated Dsg3 knockdown or the stable expression of the truncated mutant Dsg3ΔC. Our results showed that loss of Dsg3 resulted in compromised cell-cell adhesion and reduction of adherens junction and desmosome protein expression as well as the cortical F-actin formation. As a consequence, cells failed to polarize but instead displayed aberrant cell flattening. Furthermore, retardation of E-cadherin internalization and recycling was consistently observed in these cells during the process of calcium induced junction assembling. In contrast, enhanced cadherin endocytosis was detected in cells with overexpression of Dsg3 compared to control cells. Importantly, this altered cadherin trafficking was found to be coincided with the reduced expression and activity of Rab proteins, including Rab5, Rab7 and Rab11 which are known to be involved in E-cadherin trafficking. Taken together, our findings suggest that Dsg3 functions as a key in cell-cell adhesion through at least a mechanism of regulating E-cadherin membrane trafficking. PMID:27254775

Modeling cell-substrate de-adhesion dynamics under fluid shear

NASA Astrophysics Data System (ADS)

Maan, Renu; Rani, Garima; Menon, Gautam I.; Pullarkat, Pramod A.

2018-07-01

Changes in cell-substrate adhesion are believed to signal the onset of cancer metastasis, but such changes must be quantified against background levels of intrinsic heterogeneity between cells. Variations in cell-substrate adhesion strengths can be probed through biophysical measurements of cell detachment from substrates upon the application of an external force. Here, we investigate, theoretically and experimentally, the detachment of cells adhered to substrates when these cells are subjected to fluid shear. We present a theoretical framework within which we calculate the fraction of detached cells as a function of shear stress for fast ramps as well as the decay in this fraction at fixed shear stress as a function of time. Using HEK and 3T3 fibroblast cells as experimental model systems, we extract characteristic force scales for cell adhesion as well as characteristic detachment times. We estimate force-scales of  ∼500 pN associated to a single focal contact, and characteristic time-scales of s representing cell-spread-area dependent mean first passage times to the detached state at intermediate values of the shear stress. Variations in adhesion across cell types are especially prominent when cell detachment is probed by applying a time-varying shear stress. These methods can be applied to characterizing changes in cell adhesion in a variety of contexts, including metastasis.

Improved fibronectin-immobilized fibrinogen microthreads for the attachment and proliferation of fibroblasts

PubMed Central

Rajangam, Thanavel; An, Seong Soo A

2013-01-01

The aim of this study was to fabricate fibrinogen (Fbg) microfibers with different structural characteristics for the development of 3-D tissue-engineering scaffolds. Fabricated Fbg microfibers were investigated for their biomolecule encapsulation, cell adhesion, and proliferations. Microfibers with three different concentrations of Fbg (5, 10, and 15 wt%) were prepared by a gel solvent-extraction method using a silicone rubber tube. Fbg microfibers were covalently modified with fibronectin (FN) by using water-soluble 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide as the cross-linking agent. Fbg microfibers were characterized by their FN cross-linking properties, structural morphology, and in vitro degradation. Furthermore, FN/Fbg microfibers were evaluated for cell attachment and proliferation. The bio-compatibility and cell proliferation of the microfibers were assessed by measuring adenosine triphosphate activity in C2C12 fibroblast cells. Cell attachment and proliferation on microfibers were further examined using fluorescence and scanning electron microscopic images. FN loading on the microfibers was confirmed by fluorescence and infrared spectroscopy. Surface morphology was characterized by scanning electron microscopy, and showed highly aligned nanostructures for fibers made with 15 wt% Fbg, a more porous structure for fibers made with 10 wt% Fbg, and a less porous structure for those made with 5 wt% Fbg. Controlled biodegradation of the fiber was observed for 8 weeks by using an in vitro proteolytic degradation assay. Fbg microfibers with highly aligned nanostructures (15 wt%) showed enhanced biomolecule encapsulation, as well as higher cell adhesion and proliferation than another two types of FN/Fbg fibers (5 and 10 wt%) and unmodified Fbg fibers. The promising results obtained from the present study reveal that optimal structure of Fbg microfibers could be used as a potential substratum for growth factors or drug release, especially in wound healing and

MMSET deregulation affects cell cycle progression and adhesion regulons in t(4;14) myeloma plasma cells

PubMed Central

Brito, Jose L.R.; Walker, Brian; Jenner, Matthew; Dickens, Nicholas J.; Brown, Nicola J.M.; Ross, Fiona M.; Avramidou, Athanasia; Irving, Julie A.E.; Gonzalez, David; Davies, Faith E.; Morgan, Gareth J.

2009-01-01

Background The recurrent immunoglobulin translocation, t(4;14)(p16;q32) occurs in 15% of multiple myeloma patients and is associated with poor prognosis, through an unknown mechanism. The t(4;14) up-regulates fibroblast growth factor receptor 3 (FGFR3) and multiple myeloma SET domain (MMSET) genes. The involvement of MMSET in the pathogenesis of t(4;14) multiple myeloma and the mechanism or genes deregulated by MMSET upregulation are still unclear. Design and Methods The expression of MMSET was analyzed using a novel antibody. The involvement of MMSET in t(4;14) myelomagenesis was assessed by small interfering RNA mediated knockdown combined with several biological assays. In addition, the differential gene expression of MMSET-induced knockdown was analyzed with expression microarrays. MMSET gene targets in primary patient material was analyzed by expression microarrays. Results We found that MMSET isoforms are expressed in multiple myeloma cell lines, being exclusively up-regulated in t(4;14)-positive cells. Suppression of MMSET expression affected cell proliferation by both decreasing cell viability and cell cycle progression of cells with the t(4;14) translocation. These findings were associated with reduced expression of genes involved in the regulation of cell cycle progression (e.g. CCND2, CCNG1, BRCA1, AURKA and CHEK1), apoptosis (CASP1, CASP4 and FOXO3A) and cell adhesion (ADAM9 and DSG2). Furthermore, we identified genes involved in the latter processes that were differentially expressed in t(4;14) multiple myeloma patient samples. Conclusions In conclusion, dysregulation of MMSET affects the expression of several genes involved in the regulation of cell cycle progression, cell adhesion and survival. PMID:19059936

The Molecular Architecture of Cell Adhesion: Dynamic Remodeling Revealed by Videonanoscopy.

PubMed

Sergé, Arnauld

2016-01-01

The plasma membrane delimits the cell, which is the basic unit of living organisms, and is also a privileged site for cell communication with the environment. Cell adhesion can occur through cell-cell and cell-matrix contacts. Adhesion proteins such as integrins and cadherins also constitute receptors for inside-out and outside-in signaling within proteolipidic platforms. Adhesion molecule targeting and stabilization relies on specific features such as preferential segregation by the sub-membrane cytoskeleton meshwork and within membrane proteolipidic microdomains. This review presents an overview of the recent insights brought by the latest developments in microscopy, to unravel the molecular remodeling occurring at cell contacts. The dynamic aspect of cell adhesion was recently highlighted by super-resolution videomicroscopy, also named videonanoscopy. By circumventing the diffraction limit of light, nanoscopy has allowed the monitoring of molecular localization and behavior at the single-molecule level, on fixed and living cells. Accessing molecular-resolution details such as quantitatively monitoring components entering and leaving cell contacts by lateral diffusion and reversible association has revealed an unexpected plasticity. Adhesion structures can be highly specialized, such as focal adhesion in motile cells, as well as immune and neuronal synapses. Spatiotemporal reorganization of adhesion molecules, receptors, and adaptors directly relates to structure/function modulation. Assembly of these supramolecular complexes is continuously balanced by dynamic events, remodeling adhesions on various timescales, notably by molecular conformation switches, lateral diffusion within the membrane and endo/exocytosis. Pathological alterations in cell adhesion are involved in cancer evolution, through cancer stem cell interaction with stromal niches, growth, extravasation, and metastasis.

Osteoblast adhesion to orthopaedic implant alloys: Effects of cell adhesion molecules and diamond-like carbon coating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kornu, R.; Kelly, M.A.; Smith, R.L.

1996-11-01

In total joint arthroplasty, long-term outcomes depend in part on the biocompatibility of implant alloys. This study analyzed effects of surface finish and diamond-like carbon coating on osteoblast cell adhesion to polished titanium-aluminum-vanadium and polished or grit-blasted cobalt-chromium-molybdenum alloys. Osteoblast binding was tested in the presence and absence of the cell adhesion proteins fibronectin, laminin, fibrinogen, and vitronectin and was quantified by measurement of DNA content. Although adherence occurred in serum-free medium, maximal osteoblast binding required serum and was similar for titanium and cobalt alloys at 2 and 12 hours. With the grit-blasted cobalt alloy, cell binding was reduced 48%more » (p < 0.05) by 24 hours. Coating the alloys with diamond-like carbon did not alter osteoblast adhesion, whereas fibronectin pretreatment increased cell binding 2.6-fold (p < 0.05). In contrast, fibrinogen, vitronectin, and laminin did not enhance cell adhesion. These results support the hypothesis that cell adhesion proteins can modify cell binding to orthopaedic alloys. Although osteoblast binding was not affected by the presence of diamond-like carbon, this coating substance may influence other longer term processes, such as bone formation, and deserves further study. 40 refs., 4 figs.« less

Graphene supports in vitro proliferation and osteogenic differentiation of goat adult mesenchymal stem cells: potential for bone tissue engineering.

PubMed

Elkhenany, Hoda; Amelse, Lisa; Lafont, Andersen; Bourdo, Shawn; Caldwell, Marc; Neilsen, Nancy; Dervishi, Enkeleda; Derek, Oshin; Biris, Alexandru S; Anderson, David; Dhar, Madhu

2015-04-01

Current treatments for bone loss injuries involve autologous and allogenic bone grafts, metal alloys and ceramics. Although these therapies have proved useful, they suffer from inherent challenges, and hence, an adequate bone replacement therapy has not yet been found. We hypothesize that graphene may be a useful nanoscaffold for mesenchymal stem cells and will promote proliferation and differentiation into bone progenitor cells. In this study, we evaluate graphene, a biocompatible inert nanomaterial, for its effect on in vitro growth and differentiation of goat adult mesenchymal stem cells. Cell proliferation and differentiation are compared between polystyrene-coated tissue culture plates and graphene-coated plates. Graphitic materials are cytocompatible and support cell adhesion and proliferation. Importantly, cells seeded on to oxidized graphene films undergo osteogenic differentiation in fetal bovine serum-containing medium without the addition of any glucocorticoid or specific growth factors. These findings support graphene's potential to act as an osteoinducer and a vehicle to deliver mesenchymal stem cells, and suggest that the combination of graphene and goat mesenchymal stem cells provides a promising construct for bone tissue engineering. Copyright © 2014 John Wiley & Sons, Ltd.

Retinoic acid and nitric oxide promote cell proliferation and differentially induce neuronal differentiation in vitro in the cnidarian Renilla koellikeri.

PubMed

Estephane, Djoyce; Anctil, Michel

2010-10-01

Retinoic acid (RA) and nitric oxide (NO) are known to promote neuronal development in both vertebrates and invertebrates. Retinoic acid receptors appear to be present in cnidarians and NO plays various physiological roles in several cnidarians, but there is as yet no evidence that these agents have a role in neural development in this basal metazoan phylum. We used primary cultures of cells from the sea pansy Renilla koellikeri to investigate the involvement of these signaling molecules in cnidarian cell differentiation. We found that 9-cis RA induce cell proliferation in dose- and time-dependent manners in dishes coated with polylysine from the onset of culture. Cells in cultures exposed to RA in dishes devoid of polylysine were observed to differentiate into epithelium-associated cells, including sensory cells, without net gain in cell density. NO donors also induce cell proliferation in polylysine-coated dishes, but induce neuronal differentiation and neurite outgrowth in uncoated dishes. No other cell type undergoes differentiation in the presence of NO. These observations suggest that in the sea pansy (1) cell adhesion promotes proliferation without morphogenesis and this proliferation is modulated positively by 9-cis RA and NO, (2) 9-cis RA and NO differentially induce neuronal differentiation in nonadherent cells while repressing proliferation, and (3) the involvement of RA and NO in neuronal differentiation appeared early during the evolutionary emergence of nervous systems. 2010 Wiley Periodicals, Inc.

Calcium signaling and cell proliferation.

PubMed

Pinto, Mauro Cunha Xavier; Kihara, Alexandre Hiroaki; Goulart, Vânia A M; Tonelli, Fernanda M P; Gomes, Katia N; Ulrich, Henning; Resende, Rodrigo R

2015-11-01

Cell proliferation is orchestrated through diverse proteins related to calcium (Ca(2+)) signaling inside the cell. Cellular Ca(2+) influx that occurs first by various mechanisms at the plasma membrane, is then followed by absorption of Ca(2+) ions by mitochondria and endoplasmic reticulum, and, finally, there is a connection of calcium stores to the nucleus. Experimental evidence indicates that the fluctuation of Ca(2+) from the endoplasmic reticulum provides a pivotal and physiological role for cell proliferation. Ca(2+) depletion in the endoplasmatic reticulum triggers Ca(2+) influx across the plasma membrane in an phenomenon called store-operated calcium entries (SOCEs). SOCE is activated through a complex interplay between a Ca(2+) sensor, denominated STIM, localized in the endoplasmic reticulum and a Ca(2+) channel at the cell membrane, denominated Orai. The interplay between STIM and Orai proteins with cell membrane receptors and their role in cell proliferation is discussed in this review. Copyright © 2015 Elsevier Inc. All rights reserved.

Strong adhesion by regulatory T cells induces dendritic cell cytoskeletal polarization and contact-dependent lethargy.

PubMed

Chen, Jiahuan; Ganguly, Anutosh; Mucsi, Ashley D; Meng, Junchen; Yan, Jiacong; Detampel, Pascal; Munro, Fay; Zhang, Zongde; Wu, Mei; Hari, Aswin; Stenner, Melanie D; Zheng, Wencheng; Kubes, Paul; Xia, Tie; Amrein, Matthias W; Qi, Hai; Shi, Yan

2017-02-01

Dendritic cells are targeted by regulatory T (T reg) cells, in a manner that operates as an indirect mode of T cell suppression. In this study, using a combination of single-cell force spectroscopy and structured illumination microscopy, we analyze individual T reg cell-DC interaction events and show that T reg cells exhibit strong intrinsic adhesiveness to DCs. This increased DC adhesion reduces the ability of contacted DCs to engage other antigen-specific cells. We show that this unusually strong LFA-1-dependent adhesiveness of T reg cells is caused in part by their low calpain activities, which normally release integrin-cytoskeleton linkage, and thereby reduce adhesion. Super resolution imaging reveals that such T reg cell adhesion causes sequestration of Fascin-1, an actin-bundling protein essential for immunological synapse formation, and skews Fascin-1-dependent actin polarization in DCs toward the T reg cell adhesion zone. Although it is reversible upon T reg cell disengagement, this sequestration of essential cytoskeletal components causes a lethargic state of DCs, leading to reduced T cell priming. Our results reveal a dynamic cytoskeletal component underlying T reg cell-mediated DC suppression in a contact-dependent manner. © 2017 Chen et al.

Cell polarity, cell adhesion, and spermatogenesis: role of cytoskeletons

PubMed Central

Li, Linxi; Gao, Ying; Chen, Haiqi; Jesus, Tito; Tang, Elizabeth; Li, Nan; Lian, Qingquan; Ge, Ren-shan; Cheng, C. Yan

2017-01-01

In the rat testis, studies have shown that cell polarity, in particular spermatid polarity, to support spermatogenesis is conferred by the coordinated efforts of the Par-, Crumbs-, and Scribble-based polarity complexes in the seminiferous epithelium. Furthermore, planar cell polarity (PCP) is conferred by PCP proteins such as Van Gogh-like 2 (Vangl2) in the testis. On the other hand, cell junctions at the Sertoli cell–spermatid (steps 8–19) interface are exclusively supported by adhesion protein complexes (for example, α6β1-integrin-laminin-α3,β3,γ3 and nectin-3-afadin) at the actin-rich apical ectoplasmic specialization (ES) since the apical ES is the only anchoring device in step 8–19 spermatids. For cell junctions at the Sertoli cell–cell interface, they are supported by adhesion complexes at the actin-based basal ES (for example, N-cadherin-β-catenin and nectin-2-afadin), tight junction (occludin-ZO-1 and claudin 11-ZO-1), and gap junction (connexin 43-plakophilin-2) and also intermediate filament-based desmosome (for example, desmoglein-2-desmocollin-2). In short, the testis-specific actin-rich anchoring device known as ES is crucial to support spermatid and Sertoli cell adhesion. Accumulating evidence has shown that the Par-, Crumbs-, and Scribble-based polarity complexes and the PCP Vangl2 are working in concert with actin- or microtubule-based cytoskeletons (or both) and these polarity (or PCP) protein complexes exert their effects through changes in the organization of the cytoskeletal elements across the seminiferous epithelium of adult rat testes. As such, there is an intimate relationship between cell polarity, cell adhesion, and cytoskeletal function in the testis. Herein, we critically evaluate these recent findings based on studies on different animal models. We also suggest some crucial future studies to be performed. PMID:28928959

CD44-mediated hyaluronan binding marks proliferating hematopoietic progenitor cells and promotes bone marrow engraftment

PubMed Central

Lee-Sayer, Sally S. M.; Dougan, Meghan N.; Cooper, Jesse; Sanderson, Leslie; Dosanjh, Manisha; Maxwell, Christopher A.

2018-01-01

CD44 is a widely expressed cell adhesion molecule that binds to the extracellular matrix component, hyaluronan. However, this interaction is not constitutive in most immune cells at steady state, as the ability of CD44 to engage hyaluronan is highly regulated. While activated T cells and macrophages gain the ability to bind hyaluronan by CD44, the status in other immune cells is less studied. Here we found a percentage of murine eosinophils, natural killer and natural killer T cells were capable of interacting with hyaluronan at steady state. To further investigate the consequences of hyaluronan binding by CD44 in the hematopoietic system, point mutations of CD44 that either cannot bind hyaluronan (LOF-CD44) or have an increased affinity for hyaluronan (GOF-CD44) were expressed in CD44-deficient bone marrow. Competitive bone marrow reconstitution of irradiated mice revealed an early preference for GOF-CD44 over WT-CD44 expressing cells, and for WT-CD44 over LOF-CD44 expressing cells, in the hematopoietic progenitor cell compartment. The advantage of the hyaluronan-binding cells was observed in the hematopoietic stem and progenitor populations, and was maintained throughout the immune system. Hematopoietic stem cells bound minimal hyaluronan at steady state, and this was increased when the cells were induced to proliferate whereas multipotent progenitors had an increased ability to bind hyaluronan at steady state. In vitro, the addition of hyaluronan promoted their proliferation. Thus, proliferating hematopoietic progenitors bind hyaluronan, and hyaluronan binding cells have a striking competitive advantage in bone marrow engraftment. PMID:29684048

Role of cell division and self-propulsion in self-organization of 2D cell co-cultures

NASA Astrophysics Data System (ADS)

Das, Moumita; Dey, Supravat; Wu, Mingming; Ma, Minglin

Self-organization of cells is a key process in developmental and cancer biology. The differential adhesion hypothesis (DAH), which assumes cells as equilibrium liquid droplets and relates the self-assembly of cells to differences in inter-cellular adhesiveness, has been very successful in explaining cellular organization during morphogenesis where neighboring cells have the same non-equilibrium properties (motility, proliferation rate). However, recently it has been experimentally shown that for a co-culture of two different cell types proliferating at different rates, the resulting spatial morphologies cannot be explained using the DAH alone. Motivated by this, we develop and study a two-dimensional model of a cell co-culture that includes cell division and self-propulsion in addition to cell-cell adhesion, and systemically study how cells with significantly different adhesion, motility, and proliferation rate dynamically organize themselves in a spatiotemporal and context-dependent manner. Our results may help to understand how differential equilibrium and non-equilibrium properties cooperate and compete leading to different morphologies during tumor development, with important consequences for invasion and metastasis

Adhesion signaling promotes protease‑driven polyploidization of glioblastoma cells.

PubMed

Mercapide, Javier; Lorico, Aurelio

2014-11-01

An increase in ploidy (polyploidization) causes genomic instability in cancer. However, the determinants for the increased DNA content of cancer cells have not yet been fully elucidated. In the present study, we investigated whether adhesion induces polyploidization in human U87MG glioblastoma cells. For this purpose, we employed expression vectors that reported transcriptional activation by signaling networks implicated in cancer. Signaling activation induced by intercellular integrin binding elicited both extracellular signal‑regulated kinase (ERK) and Notch target transcription. Upon the prolonged activation of both ERK and Notch target transcription induced by integrin binding to adhesion protein, cell cultures accumulated polyploid cells, as determined by cell DNA content distribution analysis and the quantification of polynucleated cells. This linked the transcriptional activation induced by integrin adhesion to the increased frequency of polyploidization. Accordingly, the inhibition of signaling decreased the extent of polyploidization mediated by protease‑driven intracellular invasion. Therefore, the findings of this study indicate that integrin adhesion induces polyploidization through the stimulation of glioblastoma cell invasiveness.

Strong adhesion by regulatory T cells induces dendritic cell cytoskeletal polarization and contact-dependent lethargy

PubMed Central

Mucsi, Ashley D.; Meng, Junchen; Yan, Jiacong; Zhang, Zongde; Wu, Mei; Hari, Aswin; Stenner, Melanie D.; Zheng, Wencheng; Kubes, Paul; Xia, Tie; Amrein, Matthias W.

2017-01-01

Dendritic cells are targeted by regulatory T (T reg) cells, in a manner that operates as an indirect mode of T cell suppression. In this study, using a combination of single-cell force spectroscopy and structured illumination microscopy, we analyze individual T reg cell–DC interaction events and show that T reg cells exhibit strong intrinsic adhesiveness to DCs. This increased DC adhesion reduces the ability of contacted DCs to engage other antigen-specific cells. We show that this unusually strong LFA-1–dependent adhesiveness of T reg cells is caused in part by their low calpain activities, which normally release integrin–cytoskeleton linkage, and thereby reduce adhesion. Super resolution imaging reveals that such T reg cell adhesion causes sequestration of Fascin-1, an actin-bundling protein essential for immunological synapse formation, and skews Fascin-1–dependent actin polarization in DCs toward the T reg cell adhesion zone. Although it is reversible upon T reg cell disengagement, this sequestration of essential cytoskeletal components causes a lethargic state of DCs, leading to reduced T cell priming. Our results reveal a dynamic cytoskeletal component underlying T reg cell–mediated DC suppression in a contact-dependent manner. PMID:28082358

Increased endothelial cell adhesion and elongation on micron-patterned nano-rough poly(dimethylsiloxane) films.

PubMed

Ranjan, Ashwini; Webster, Thomas J

2009-07-29

The success of synthetic vascular grafts is largely determined by their ability to promote vital endothelial cell functions such as adhesion, alignment, proliferation, and extracellular matrix (ECM) deposition. Developing such biomaterials requires the design and fabrication of materials that mimic select properties of native extracellular matrices. Furthermore, cells of the native endothelium have elongated and aligned morphology in the direction of blood flow, yet few materials promote this type of morphology initially, but rather rely on blood flow to orient endothelial cells. Therefore, the objective of this in vitro study was to design a biomaterial that mimics the conditions of the micro- and nano-environment of vascular intima tissue suitable for endothelial cell adhesion and elongation to improve the efficacy of small synthetic vascular grafts. Towards this end, patterned poly(dimethylsiloxane) (PDMS) films consisting of periodic arrays of nano-grooves (500 nm), with spacings ranging from 22 to 80 microm, and alternating nano- and micron roughness were fabricated using a novel electron beam physical vapor deposition method followed by polymer casting. By varying pattern spacing, the area of micron- and nano-rough surface was controlled. In vitro rat aortic endothelial cell adhesion and elongation studies indicated that endothelial cell function was enhanced on patterned PDMS surfaces with the widest spacing and greatest surface area of nano-roughness, as compared to more narrow pattern spacings and non-patterned PDMS surfaces. Specifically, endothelial cells adherent on PDMS patterned films of the widest spacing (greatest nano-rough area) displayed almost twice as much elongation as cells on non-patterned surfaces. For these reasons, the present study highlighted design criteria (the use of micron patterns of nano-features on PDMS) that may contribute to the intelligent design of new-generation vascular grafts.

Nanometer polymer surface features: the influence on surface energy, protein adsorption and endothelial cell adhesion

NASA Astrophysics Data System (ADS)

Carpenter, Joseph; Khang, Dongwoo; Webster, Thomas J.

2008-12-01

Current small diameter (<5 mm) synthetic vascular graft materials exhibit poor long-term patency due to thrombosis and intimal hyperplasia. Tissue engineered solutions have yielded functional vascular tissue, but some require an eight-week in vitro culture period prior to implantation—too long for immediate clinical bedside applications. Previous in vitro studies have shown that nanostructured poly(lactic-co-glycolic acid) (PLGA) surfaces elevated endothelial cell adhesion, proliferation, and extracellular matrix synthesis when compared to nanosmooth surfaces. Nonetheless, these studies failed to address the importance of lateral and vertical surface feature dimensionality coupled with surface free energy; nor did such studies elicit an optimum specific surface feature size for promoting endothelial cell adhesion. In this study, a series of highly ordered nanometer to submicron structured PLGA surfaces of identical chemistry were created using a technique employing polystyrene nanobeads and poly(dimethylsiloxane) (PDMS) molds. Results demonstrated increased endothelial cell adhesion on PLGA surfaces with vertical surface features of size less than 18.87 nm but greater than 0 nm due to increased surface energy and subsequently protein (fibronectin and collagen type IV) adsorption. Furthermore, this study provided evidence that the vertical dimension of nanometer surface features, rather than the lateral dimension, is largely responsible for these increases. In this manner, this study provides key design parameters that may promote vascular graft efficacy.

Amphiphilic cationic peptides mediate cell adhesion to plastic surfaces.

PubMed

Rideout, D C; Lambert, M; Kendall, D A; Moe, G R; Osterman, D G; Tao, H P; Weinstein, I B; Kaiser, E T

1985-09-01

Four amphiphilic peptides, each with net charges of +2 or more at neutrality and molecular weights under 4 kilodaltons, were found to mediate the adhesion of normal rat kidney fibroblasts to polystyrene surfaces. Two of these peptides, a model for calcitonin (peptide 1, MCT) and melittin (peptide 2, MEL), form amphiphilic alpha-helical structures at aqueous/nonpolar interfaces. The other two, a luteinizing hormone-releasing hormone model (peptide 3, LHM) and a platelet factor model (peptide 4, MPF) form beta-strand structures in amphiphilic environments. Although it contains only 10 residues, LHM mediated adhesion to surfaces coated with solutions containing as little as 10 pmoles/ml of peptide. All four of these peptides were capable of forming monolayers at air-buffer interfaces with collapse pressures greater than 20 dynes/cm. None of these four peptides contains the tetrapeptide sequence Arg-Gly-Asp-Ser, which has been associated with fibronectin-mediated cell adhesion. Ten polypeptides that also lacked the sequence Arg-Gly-Asp-Ser but were nonamphiphilic and/or had net charges less than +2 at neutrality were all incapable of mediating cell adhesion (Pierschbacher and Ruoslahti, 1984). The morphologies of NRK cells spread on polystyrene coated with peptide LHM resemble the morphologies on fibronectin-coated surfaces, whereas cells spread on surfaces coated with MCT or MEL exhibit strikingly different morphologies. The adhesiveness of MCT, MEL, LHM, and MPF implies that many amphiphilic cationic peptides could prove useful as well defined adhesive substrata for cell culture and for studies of the mechanism of cell adhesion.

Cell-Adhesive Matrices Composed of RGD Peptide-Displaying M13 Bacteriophage/Poly(lactic-co-glycolic acid) Nanofibers Beneficial to Myoblast Differentiation.

PubMed

Shin, Yong Cheol; Lee, Jong Ho; Jin, Linhua; Kim, Min Jeong; Kim, Chuntae; Hong, Suck Won; Oh, Jin Woo; Han, Dong-Wook

2015-10-01

Recently, there has been considerable effort to develop suitable scaffolds for tissue engineering applications. Cell adhesion is a prerequisite for cells to survive. In nature, the extracellular matrix (ECM) plays this role. Therefore, an ideal scaffold should be structurally similar to the natural ECM and have biocompatibility and biodegradability. In addition, the scaffold should have biofunctionality, which provides the potent ability to enhance the cellular behaviors, such as adhesion, proliferation and differentiation. This study concentrates on fabricating cell-adhesive matrices composed of RGD peptide-displaying M13 bacteriophage (RGD-M13 phage) and poly(lactic-co-glycolic acid, PLGA) nanofibers. Long rod-shaped M13 bacteriophages are non-toxic and can express many desired proteins on their surface. A genetically engineered M13 phage was constructed to display RGD peptides on its surface. PLGA is a biodegradable polymer with excellent biocompatibility and suitable physicochemical property for adhesive matrices. In this study, RGD-M13 phage/PLGA hybrid nanofiber matrices were fabricated by electrospinning. The physicochemical properties of these matrices were characterized by scanning electron microscopy, atomic force microscopy, Raman spectroscopy, and contact angle measurement. In addition, the cellular behaviors, such as the initial attachment, proliferation and differentiation, were analyzed by a CCK-8 assay and immunofluorescence staining to evaluate the potential application of these matrices to tissue engineering scaffolds. The RGD-M13 phage/PLGA nanofiber matrices could enhance the cellular behaviors and promote the differentiation of C2C12 myoblasts. These results suggest that the RGD-M13 phage/PLGA nanofiber matrices are beneficial to myoblast differentiation and can serve as effective tissue engineering scaffolds.

Molecules mediating adhesion of T and B cells, monocytes and granulocytes to vascular endothelial cells.

PubMed Central

Prieto, J; Beatty, P G; Clark, E A; Patarroyo, M

1988-01-01

Leucocytes interact with vascular endothelial cells (EC), and adhesion between these two cell types in vitro is modulated by phorbol ester. Monocytes were found to display the highest basal adhesion to EC, followed by Epstein-Barr virus-immortalized normal B cells (EBV-B), T cells and granulocytes. Phorbol ester treatment increased the adhesion of all types of leucocytes, except monocytes. In the presence of this compound, monoclonal antibody 60.3 to GP90 (CD18, a leucocyte-adhesion protein which is non-covalently associated to either GP160, GP155, or GP130) was found to inhibit the adhesion of the four types of leucocytes to a considerable extent, while anti-lymphocyte function-associated antigen-1 (LFA-1) antibody to GP160 (CD11a) inhibited the adhesion of T and B cells only. Antibody 60.1 to GP155 (CD11b) had a major inhibitory activity exclusively on granulocytes, while antibody LB-2, which recognizes a distinct adhesion molecule (GP84) and, in contrast to the previous antibodies, reacts with EC, mainly inhibited adhesion of EBV-B and did not increase the inhibition obtained with antibody 60.3 alone. Fab fragments of antibody 60.3 inhibited leucocyte adhesion more efficiently, in either the absence or presence of phorbol ester, than the intact antibody molecule. It is concluded the GP90, either alone or associated to the larger glycoproteins, mediates the adhesion in all types of leucocytes, while GP84 mediates the adhesion of the activated B cells. Images Figure 2 PMID:3259203

Cell adhesion during bullet motion in capillaries.

PubMed

Takeishi, Naoki; Imai, Yohsuke; Ishida, Shunichi; Omori, Toshihiro; Kamm, Roger D; Ishikawa, Takuji

2016-08-01

A numerical analysis is presented of cell adhesion in capillaries whose diameter is comparable to or smaller than that of the cell. In contrast to a large number of previous efforts on leukocyte and tumor cell rolling, much is still unknown about cell motion in capillaries. The solid and fluid mechanics of a cell in flow was coupled with a slip bond model of ligand-receptor interactions. When the size of a capillary was reduced, the cell always transitioned to "bullet-like" motion, with a consequent decrease in the velocity of the cell. A state diagram was obtained for various values of capillary diameter and receptor density. We found that bullet motion enables firm adhesion of a cell to the capillary wall even for a weak ligand-receptor binding. We also quantified effects of various parameters, including the dissociation rate constant, the spring constant, and the reactive compliance on the characteristics of cell motion. Our results suggest that even under the interaction between P-selectin glycoprotein ligand-1 (PSGL-1) and P-selectin, which is mainly responsible for leukocyte rolling, a cell is able to show firm adhesion in a small capillary. These findings may help in understanding such phenomena as leukocyte plugging and cancer metastasis. Copyright © 2016 the American Physiological Society.

Wnt signaling regulates pancreatic β cell proliferation

PubMed Central

Rulifson, Ingrid C.; Karnik, Satyajit K.; Heiser, Patrick W.; ten Berge, Derk; Chen, Hainan; Gu, Xueying; Taketo, Makoto M.; Nusse, Roel; Hebrok, Matthias; Kim, Seung K.

2007-01-01

There is widespread interest in defining factors and mechanisms that stimulate proliferation of pancreatic islet cells. Wnt signaling is an important regulator of organ growth and cell fates, and genes encoding Wnt-signaling factors are expressed in the pancreas. However, it is unclear whether Wnt signaling regulates pancreatic islet proliferation and differentiation. Here we provide evidence that Wnt signaling stimulates islet β cell proliferation. The addition of purified Wnt3a protein to cultured β cells or islets promoted expression of Pitx2, a direct target of Wnt signaling, and Cyclin D2, an essential regulator of β cell cycle progression, and led to increased β cell proliferation in vitro. Conditional pancreatic β cell expression of activated β-catenin, a crucial Wnt signal transduction protein, produced similar phenotypes in vivo, leading to β cell expansion, increased insulin production and serum levels, and enhanced glucose handling. Conditional β cell expression of Axin, a potent negative regulator of Wnt signaling, led to reduced Pitx2 and Cyclin D2 expression by β cells, resulting in reduced neonatal β cell expansion and mass and impaired glucose tolerance. Thus, Wnt signaling is both necessary and sufficient for islet β cell proliferation, and our study provides previously unrecognized evidence of a mechanism governing endocrine pancreas growth and function. PMID:17404238

The Drosophila cell adhesion molecule Neuroglian regulates Lissencephaly-1 localisation in circulating immunosurveillance cells.

PubMed

Williams, Michael J

2009-03-25

When the parasitoid wasp Leptopilina boulardi lays its eggs in Drosophila larvae phagocytic cells called plasmatocytes and specialized cells known as lamellocytes encapsulate the egg. This requires these circulating immunosurveillance cells (haemocytes) to change from a non-adhesive to an adhesive state enabling them to bind to the invader. Interestingly, attachment of leukocytes, platelets, and insect haemocytes requires the same adhesion complexes as epithelial and neuronal cells. Here evidence is presented showing that the Drosophila L1-type cell adhesion molecule Neuroglian (Nrg) is required for haemocytes to encapsulate L. boulardi wasp eggs. The amino acid sequence FIGQY containing a conserved phosphorylated tyrosine is found in the intracellular domain of all L1-type cell adhesion molecules. This conserved tyrosine is phosphorylated at the cell periphery of plasmatocytes and lamellocytes prior to parasitisation, but dephosphorylated after immune activation. Intriguingly, another pool of Nrg located near the nucleus of plasmatocytes remains phosphorylated after parasitisation. In mammalian neuronal cells phosphorylated neurofascin, another L1-type cell adhesion molecule interacts with a nucleokinesis complex containing the microtubule binding protein lissencephaly-1 (Lis1) 1. Interestingly in plasmatocytes from Nrg mutants the nucleokinesis regulating protein Lissencephaly-1 (Lis1) fails to localise properly around the nucleus and is instead found diffuse throughout the cytoplasm and at unidentified perinuclear structures. After attaching to the wasp egg control plasmatocytes extend filopodia laterally from their cell periphery; as well as extending lateral filopodia plasmatocytes from Nrg mutants also extend many filopodia from their apical surface. The Drosophila cellular adhesion molecule Neuroglian is expressed in haemocytes and its activity is required for the encapsulation of L. boularli eggs. At the cell periphery of haemocytes Neuroglian may be

The Drosophila cell adhesion molecule Neuroglian regulates Lissencephaly-1 localisation in circulating immunosurveillance cells

PubMed Central

Williams, Michael J

2009-01-01

Background When the parasitoid wasp Leptopilina boulardi lays its eggs in Drosophila larvae phagocytic cells called plasmatocytes and specialized cells known as lamellocytes encapsulate the egg. This requires these circulating immunosurveillance cells (haemocytes) to change from a non-adhesive to an adhesive state enabling them to bind to the invader. Interestingly, attachment of leukocytes, platelets, and insect haemocytes requires the same adhesion complexes as epithelial and neuronal cells. Results Here evidence is presented showing that the Drosophila L1-type cell adhesion molecule Neuroglian (Nrg) is required for haemocytes to encapsulate L. boulardi wasp eggs. The amino acid sequence FIGQY containing a conserved phosphorylated tyrosine is found in the intracellular domain of all L1-type cell adhesion molecules. This conserved tyrosine is phosphorylated at the cell periphery of plasmatocytes and lamellocytes prior to parasitisation, but dephosphorylated after immune activation. Intriguingly, another pool of Nrg located near the nucleus of plasmatocytes remains phosphorylated after parasitisation. In mammalian neuronal cells phosphorylated neurofascin, another L1-type cell adhesion molecule interacts with a nucleokinesis complex containing the microtubule binding protein lissencephaly-1 (Lis1) [1]. Interestingly in plasmatocytes from Nrg mutants the nucleokinesis regulating protein Lissencephaly-1 (Lis1) fails to localise properly around the nucleus and is instead found diffuse throughout the cytoplasm and at unidentified perinuclear structures. After attaching to the wasp egg control plasmatocytes extend filopodia laterally from their cell periphery; as well as extending lateral filopodia plasmatocytes from Nrg mutants also extend many filopodia from their apical surface. Conclusion The Drosophila cellular adhesion molecule Neuroglian is expressed in haemocytes and its activity is required for the encapsulation of L. boularli eggs. At the cell periphery of