scholarly journals The Impact of Spaceflight and Simulated Microgravity on Cell Adhesion

2020 ◽  
Vol 21 (9) ◽  
pp. 3031 ◽  
Author(s):  
Xiao Lin ◽  
Kewen Zhang ◽  
Daixu Wei ◽  
Ye Tian ◽  
Yongguang Gao ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Mammalian Cells ◽  
Simulated Microgravity ◽  
General Term ◽  
Cellular Adhesion ◽  
Immunoglobulin Superfamily ◽  
Adhesion Properties ◽  
Cellular Adhesion Molecule ◽  
The Impact ◽  
Cell Cell

Microgravity induces a number of significant physiological changes in the cardiovascular, nervous, immune systems, as well as the bone tissue of astronauts. Changes in cell adhesion properties are one aspect affected during long-term spaceflights in mammalian cells. Cellular adhesion behaviors can be divided into cell–cell and cell–matrix adhesion. These behaviors trigger cell–cell recognition, conjugation, migration, cytoskeletal rearrangement, and signal transduction. Cellular adhesion molecule (CAM) is a general term for macromolecules that mediate the contact and binding between cells or between cells and the extracellular matrix (ECM). In this review, we summarize the four major classes of adhesion molecules that regulate cell adhesion, including integrins, immunoglobulin superfamily (Ig-SF), cadherins, and selectin. Moreover, we discuss the effects of spaceflight and simulated microgravity on the adhesion of endothelial cells, immune cells, tumor cells, stem cells, osteoblasts, muscle cells, and other types of cells. Further studies on the effects of microgravity on cell adhesion and the corresponding physiological behaviors may help increase the safety and improve the health of astronauts in space.

scholarly journals The Role of MicroRNAs in Epidermal Barrier

2020 ◽  
Vol 21 (16) ◽  
pp. 5781
Author(s):  
Ai-Young Lee
Keyword(s):  
Cell Adhesion ◽  
Critical Role ◽  
Keratinocyte Differentiation ◽  
Epidermal Barrier ◽  
Barrier Integrity ◽  
Skin Lipids ◽  
Differentiation And Proliferation ◽  
The Impact ◽  
Cell Cell

MicroRNAs (miRNAs), which mostly cause target gene silencing via transcriptional repression and degradation of target mRNAs, regulate a plethora of cellular activities, such as cell growth, differentiation, development, and apoptosis. In the case of skin keratinocytes, the role of miRNA in epidermal barrier integrity has been identified. Based on the impact of key genetic and environmental factors on the integrity and maintenance of skin barrier, the association of miRNAs within epidermal cell differentiation and proliferation, cell–cell adhesion, and skin lipids is reviewed. The critical role of miRNAs in the epidermal barrier extends the use of miRNAs for control of relevant skin diseases such as atopic dermatitis, ichthyoses, and psoriasis via miRNA-based technologies. Most of the relevant miRNAs have been associated with keratinocyte differentiation and proliferation. Few studies have investigated the association of miRNAs with structural proteins of corneocytes and cornified envelopes, cell–cell adhesion, and skin lipids. Further studies investigating the association between regulatory and structural components of epidermal barrier and miRNAs are needed to elucidate the role of miRNAs in epidermal barrier integrity and their clinical implications.

scholarly journals The Role of Immunoglobulin Superfamily Cell Adhesion Molecules in Cancer Metastasis

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Chee Wai Wong ◽  
Danielle E. Dye ◽  
Deirdre R. Coombe
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecules ◽  
Cancer Progression ◽  
Cell Adhesion Molecules ◽  
Cancer Metastasis ◽  
Clinical Problem ◽  
Metastatic Lesion ◽  
Immunoglobulin Superfamily ◽  
Metastatic Pathway ◽  
Cell Cell

Metastasis is a major clinical problem and results in a poor prognosis for most cancers. The metastatic pathway describes the process by which cancer cells give rise to a metastatic lesion in a new tissue or organ. It consists of interconnecting steps all of which must be successfully completed to result in a metastasis. Cell-cell adhesion is a key aspect of many of these steps. Adhesion molecules belonging to the immunoglobulin superfamily (Ig-SF) commonly play a central role in cell-cell adhesion, and a number of these molecules have been associated with cancer progression and a metastatic phenotype. Surprisingly, the contribution of Ig-SF members to metastasis has not received the attention afforded other cell adhesion molecules (CAMs) such as the integrins. Here we examine the steps in the metastatic pathway focusing on how the Ig-SF members, melanoma cell adhesion molecule (MCAM), L1CAM, neural CAM (NCAM), leukocyte CAM (ALCAM), intercellular CAM-1 (ICAM-1) and platelet endothelial CAM-1 (PECAM-1) could play a role. Although much remains to be understood, this review aims to raise the profile of Ig-SF members in metastasis formation and prompt further research that could lead to useful clinical outcomes.

Effects of Albumin Adsorption on Cell Adhesion in Hydroxyapatite Modified Surfaces

2014 ◽  
Vol 631 ◽  
pp. 351-356 ◽  
Author(s):  
Juliana Côrtes ◽  
Elena Mavropoulos ◽  
Moema Hausen ◽  
Alexandre Rossi ◽  
Gutemberg Alves
Keyword(s):  
Cell Adhesion ◽  
Neutral Red ◽  
Cellular Adhesion ◽  
Modified Surfaces ◽  
Osteoblast Adhesion ◽  
Synthetic Hydroxyapatite ◽  
Albumin Adsorption ◽  
The Impact ◽  
Protein Treatment ◽  
Mitochondrial Dehydrogenase Activity

Synthetic hydroxyapatite (HA) is a widely used ceramic biomaterial due to its well described biocompatibility. Some modifications in HA surface can be made to increase surface porosity. Likewise, HA can be modified by the coating with proteins, which may impact on biocompatibility. In this work, we aimed to evaluate the impact of two surface modifications – coating with albumin, a major serum protein, and augmented porosity - over osteoblast adhesion on stoichiometric HA discs. Dense HA discs were obtained by pressing HA powder at 30 KN and sinterization at 1000°C, while porous HA was molded after the addition of alginate (15:1), followed by thermal treatment. Protein adsorption was attained by incubation on 0.5mg/mL bovine serum albumin (BSA) for 24 h at 37°C. MC3T3 mouse preosteoblasts were seeded over both protein-coated and uncoated dense or porous tablets, and cell viability after 24 h was estimated by XTT and Neutral Red assays. Cell density was quantified by fluorescence microscopy. While both dense and porous discs presented altered surfaces after protein treatment, as observed by scanning electron microscopy, porous HA tablets presented significantly higher levels of adsorbed protein. There was a decrease in the concentration of calcium ions in all samples analyzed. Porous HA treated with protein presented significant higher mitochondrial dehydrogenase activity (XTT) than non treated tablets (p<0.001). Although the BSA adsorption didn`t affect cell adhesion, the results obtained in fluorescence quantification suggests that de dense surface was best for cellular adhesion and spread than the porous one. We conclude that differences in the topography of a biomaterial can directly influence their ability to adsorb proteins, while the dense surface was more favorable for both the adhesion and the spreading of pre-osteoblasts.

scholarly journals Wnt-1 modulates cell-cell adhesion in mammalian cells by stabilizing beta-catenin binding to the cell adhesion protein cadherin

1994 ◽  
Vol 124 (5) ◽  
pp. 729-741 ◽  
Author(s):  
L Hinck ◽  
WJ Nelson ◽  
J Papkoff
Keyword(s):  
Cell Adhesion ◽  
Mammalian Cells ◽  
Signal Transduction Pathway ◽  
Beta Catenin ◽  
Adhesion Protein ◽  
Calcium Dependent ◽  
Cell Adhesion Protein ◽  
Segment Polarity ◽  
Dependent Cell ◽  
Cell Cell

Wnt-1 homologs have been identified in invertebrates and vertebrates and play important roles in cellular differentiation and organization. In Drosophila, the products of the segment polarity genes wingless (the Wnt-1 homolog) and armadillo participate in a signal transduction pathway important for cellular boundary formation in embryonic development, but functional interactions between the proteins are unknown. We have examined Wnt-1 function in mammalian cells in which armadillo (beta-catenin and plakoglobin) is known to bind to and regulate cadherin cell adhesion proteins. We show that Wnt-1 expression results in the accumulation of beta-catenin and plakoglobin. In addition, binding of beta-catenin to the cell adhesion protein, cadherin, is stabilized, resulting in a concomitant increase in the strength of calcium-dependent cell-cell adhesion. Thus, a consequence of the functional interaction between Wnt-1 and armadillo family members is the strengthening of cell-cell adhesion, which may lead to the specification of cellular boundaries.

scholarly journals Molecular basis of sidekick-mediated cell-cell adhesion and specificity

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Kerry M Goodman ◽  
Masahito Yamagata ◽  
Xiangshu Jin ◽  
Seetha Mannepalli ◽  
Phinikoula S Katsamba ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Cell Aggregation ◽  
Immunoglobulin Superfamily ◽  
Retinal Neurons ◽  
Isolated Cells ◽  
Recognition Specificity ◽  
Mediate Cell ◽  
Cis And Trans ◽  
Cell Adhesion Proteins ◽  
Cell Cell

Sidekick (Sdk) 1 and 2 are related immunoglobulin superfamily cell adhesion proteins required for appropriate synaptic connections between specific subtypes of retinal neurons. Sdks mediate cell-cell adhesion with homophilic specificity that underlies their neuronal targeting function. Here we report crystal structures of Sdk1 and Sdk2 ectodomain regions, revealing similar homodimers mediated by the four N-terminal immunoglobulin domains (Ig1–4), arranged in a horseshoe conformation. These Ig1–4 horseshoes interact in a novel back-to-back orientation in both homodimers through Ig1:Ig2, Ig1:Ig1 and Ig3:Ig4 interactions. Structure-guided mutagenesis results show that this canonical dimer is required for both Sdk-mediated cell aggregation (via trans interactions) and Sdk clustering in isolated cells (via cis interactions). Sdk1/Sdk2 recognition specificity is encoded across Ig1–4, with Ig1–2 conferring the majority of binding affinity and differential specificity. We suggest that competition between cis and trans interactions provides a novel mechanism to sharpen the specificity of cell-cell interactions.

scholarly journals The Impact of Bioactive Surfaces in the Early Stages of Osseointegration: An In Vitro Comparative Study Evaluating the HAnano® and SLActive® Super Hydrophilic Surfaces

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Rodrigo A. da Silva ◽  
Geórgia da Silva Feltran ◽  
Marcel Rodrigues Ferreira ◽  
Patrícia Fretes Wood ◽  
Fabio Bezerra ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Adhesion ◽  
Cell Cycle Progression ◽  
Cellular Adhesion ◽  
Biological Behavior ◽  
Early Stages ◽  
Genes Encoding ◽  
Bioactive Surfaces ◽  
The Impact

There is an increased effort on developing novel and active surfaces in order to accelerate their osteointegration, such as nanosized crystalline hydroxyapatite coating (HAnano®). To better understand the biological behavior of osteoblasts grown on HAnano® surface, the set of data was compared with SLActive®, a hydrophilic sandblasted titanium surface. Methodologically, osteoblasts were seeded on both surfaces up to 72 hours, to allow evaluating cell adhesion, viability, and set of genes encoding proteins related with adhesion, proliferation, and differentiation. Our data shows HAnano® displays an interesting substrate to support cell adhesion with typical spread morphologic cells, while SLActive®-adhering cells presented fusiform morphology. Our data shows that the cellular adhesion mechanism was accompanied with upexpression of integrin β1, Fak, and Src, favoring the assembling of focal adhesion platforms and coupling cell cycle progression (upmodulating of Cdk2, Cdk4, and Cdk6 genes) in response to HAnano®. Additionally, both bioactive surfaces promoted osteoblast differentiation stimulus, by activating Runx2, Osterix, and Alp genes. Although both surfaces promoted Rankl gene expression, Opg gene expression was higher in SLActive® and this difference reflected on the Rankl/Opg ratio. Finally, Caspase1 gene was significantly upmodulated in response to HAnano® and it suggests an involvement of the inflammasome complex. Collectively, this study provides enough evidences to support that the nanohydroxyapatite-coated surface provides the necessary microenvironment to drive osteoblast performance on dental implants and these stages of osteogenesis are expected during the early stages of osseointegration.

scholarly journals Ep-CAM: a human epithelial antigen is a homophilic cell-cell adhesion molecule.

1994 ◽  
Vol 125 (2) ◽  
pp. 437-446 ◽  
Author(s):  
S V Litvinov ◽  
M P Velders ◽  
H A Bakker ◽  
G J Fleuren ◽  
S O Warnaar
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecules ◽  
Adhesion Molecule ◽  
Morphological Changes ◽  
Intercellular Adhesion ◽  
Biological Behavior ◽  
Intercellular Adhesion Molecule ◽  
Immunoglobulin Superfamily ◽  
L Cells ◽  
Cell Cell

The epithelial glycoprotein 40 (EGP40, also known as GA733-2, ESA, KSA, and the 17-1A antigen), encoded by the GA-733-2 gene, is expressed on the baso-lateral cell surface in most human simple epithelia. The protein is also expressed in the vast majority of carcinomas and has attracted attention as a tumor marker. The function of the protein is unknown. We demonstrate here that EGP40 is an epithelium-specific intercellular adhesion molecule. The molecule mediates, in a Ca(2+)-independent manner, a homophilic cell-cell adhesion of murine cells transfected with the complete EGP40 cDNA. Two murine cell lines were tested for the effects of EGP40 expression: fibroblastic L cells and dedifferentiated mammary carcinoma L153S cells. The expression of the EGP40 protein causes morphological changes in cultures of transfected cells--increasing intercellular adhesion of the transfectants--and has a clear effect on cell aggregating behavior in suspension aggregation assays. EGP40 directs sorting in mixed cell populations, in particular, causes segregation of the transfectants from the corresponding parental cells. EGP40 expression suppresses invasive colony growth of L cells in EHS-matrigel providing tight adhesions between cells in growing colonies. EGP40 can thus be considered a new member of the intercellular adhesion molecules. In its biological behavior EGP40 resembles to some extent the molecules of the immunoglobulin superfamily of cell adhesion molecules (CAMs), although no immunoglobulin-like repeats are present in the EGP40 molecule. Certain structural similarities in general organization of the molecule exist between EGP40 and the lin-12/Notch proteins. A possible role of this adhesion molecule in formation of architecture of epithelial tissues is discussed. To reflect the function of the molecule the name Ep-CAM for EGP40 seems appropriate.

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