Localisation cellulaire du calcium chez le champignon Ascomycète Sphaerostilbe repens par analyse directe à la microsonde électronique

1980 ◽  
Vol 58 (22) ◽  
pp. 2395-2401 ◽  
Author(s):  
B. Botton ◽  
A. Fourcy ◽  
J. P. Bossy
Keyword(s):  
Cell Adhesion ◽  
Cell Walls ◽  
Calcium Concentration ◽  
Vegetative Mycelium ◽  
High Calcium ◽  
Sphaerostilbe Repens ◽  
Cell To Cell Adhesion

In the Ascomycete Sphaerostilbe repens, where calcium is necessary for the differentiation of aggregated organs, microlocalization of calcium was determined both in undifferentiated mycelium and in rhizomorphs. In every case cell walls contained high calcium concentrations. Mucilaginous compounds around cells also contain this cation but at a lower level.In the vegetative mycelium, Woronin bodies and particularily mitochondria accumulated calcium. In the vacuoles of rhizomorph cells, calcium concentration was low.Calcium location in cell walls suggests that this element could play a role in cell-to-cell adhesion.

ROCK2 Regulates the Expression of Cell Adhesion Molecules and Cell-to-Cell Adhesion in Vascular Endothelial Cells

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 476-P
Author(s):  
YUSUKE TAKEDA ◽  
KEIICHIRO MATOBA ◽  
DAIJI KAWANAMI ◽  
YOSUKE NAGAI ◽  
TOMOYO AKAMINE ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Adhesion ◽  
Adhesion Molecules ◽  
Cell Adhesion Molecules ◽  
Vascular Endothelial Cells ◽  
Vascular Endothelial ◽  
Cell To Cell Adhesion

scholarly journals Integrins: An Important Link between Angiogenesis, Inflammation and Eye Diseases

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1703
Author(s):  
Małgorzata Mrugacz ◽  
Anna Bryl ◽  
Mariusz Falkowski ◽  
Katarzyna Zorena
Keyword(s):  
Cell Adhesion ◽  
Tissue Repair ◽  
Normal Development ◽  
Cell Attachment ◽  
Biological Activities ◽  
Integrin Receptors ◽  
Cytokine Activation ◽  
Eye Disorders ◽  
Membrane Bound ◽  
Cell To Cell Adhesion

Integrins belong to a group of cell adhesion molecules (CAMs) which is a large group of membrane-bound proteins. They are responsible for cell attachment to the extracellular matrix (ECM) and signal transduction from the ECM to the cells. Integrins take part in many other biological activities, such as extravasation, cell-to-cell adhesion, migration, cytokine activation and release, and act as receptors for some viruses, including severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). They play a pivotal role in cell proliferation, migration, apoptosis, tissue repair and are involved in the processes that are crucial to infection, inflammation and angiogenesis. Integrins have an important part in normal development and tissue homeostasis, and also in the development of pathological processes in the eye. This review presents the available evidence from human and animal research into integrin structure, classification, function and their role in inflammation, infection and angiogenesis in ocular diseases. Integrin receptors and ligands are clinically interesting and may be promising as new therapeutic targets in the treatment of some eye disorders.

scholarly journals Differences in a Single Extracellular Residue Underlie Adhesive Functions of Two Zebrafish Aqp0s

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2005
Author(s):  
Irene Vorontsova ◽  
James E. Hall ◽  
Thomas F. Schilling ◽  
Noriaki Nagai ◽  
Yosuke Nakazawa
Keyword(s):  
Cell Adhesion ◽  
Single Amino Acid ◽  
Amino Acid Difference ◽  
Adhesion Assay ◽  
Loss Of Function ◽  
Adhesive Properties ◽  
The Difference ◽  
In Vitro Adhesion ◽  
Cell To Cell Adhesion

Aquaporin 0 (AQP0) is the most abundant lens membrane protein, and loss of function in human and animal models leads to cataract formation. AQP0 has several functions in the lens including water transport and adhesion. Since lens optics rely on strict tissue architecture achieved by compact cell-to-cell adhesion between lens fiber cells, understanding how AQP0 contributes to adhesion would shed light on normal lens physiology and pathophysiology. We show in an in vitro adhesion assay that one of two closely related zebrafish Aqp0s, Aqp0b, has strong auto-adhesive properties while Aqp0a does not. The difference appears to be largely due to a single amino acid difference at residue 110 in the extracellular C-loop, which is T in Aqp0a and N in Aqp0b. Similarly, P110 is the key residue required for adhesion in mammalian AQP0, highlighting the importance of residue 110 in AQP0 cell-to-cell adhesion in vertebrate lenses as well as the divergence of adhesive and water permeability functions in zebrafish duplicates.

The origin of passive force enhancement in skeletal muscle

2008 ◽  
Vol 294 (1) ◽  
pp. C74-C78 ◽  
Author(s):  
V. Joumaa ◽  
D. E. Rassier ◽  
T. R. Leonard ◽  
W. Herzog
Keyword(s):  
Calcium Concentration ◽  
Force Production ◽  
Primary Source ◽  
Passive Force ◽  
Active Force ◽  
Force Enhancement ◽  
Bridge Formation ◽  
Calcium Dependent ◽  
Cross Bridge ◽  
High Calcium

The aim of the present study was to test whether titin is a calcium-dependent spring and whether it is the source of the passive force enhancement observed in muscle and single fiber preparations. We measured passive force enhancement in troponin C (TnC)-depleted myofibrils in which active force production was completely eliminated. The TnC-depleted construct allowed for the investigation of the effect of calcium concentration on passive force, without the confounding effects of actin-myosin cross-bridge formation and active force production. Passive forces in TnC-depleted myofibrils ( n = 6) were 35.0 ± 2.9 nN/ μm2 when stretched to an average sarcomere length of 3.4 μm in a solution with low calcium concentration (pCa 8.0). Passive forces in the same myofibrils increased by 25% to 30% when stretches were performed in a solution with high calcium concentration (pCa 3.5). Since it is well accepted that titin is the primary source for passive force in rabbit psoas myofibrils and since the increase in passive force in TnC-depleted myofibrils was abolished after trypsin treatment, our results suggest that increasing calcium concentration is associated with increased titin stiffness. However, this calcium-induced titin stiffness accounted for only ∼25% of the passive force enhancement observed in intact myofibrils. Therefore, ∼75% of the normally occurring passive force enhancement remains unexplained. The findings of the present study suggest that passive force enhancement is partly caused by a calcium-induced increase in titin stiffness but also requires cross-bridge formation and/or active force production for full manifestation.

INHIBITORY ACTION OF CALCIUM ON THE INACTIVATION OF ANTIDIURETIC HORMONE BY RAT KIDNEY SLICES

1963 ◽  
Vol 44 (4) ◽  
pp. 563-569 ◽  
Author(s):  
N. A. Thorn ◽  
N. B. S. Willumsen
Keyword(s):  
Arginine Vasopressin ◽  
Inhibitory Action ◽  
Calcium Concentration ◽  
Rat Kidney ◽  
Kidney Medulla ◽  
Marked Inhibition ◽  
High Calcium ◽  
Rational Explanation ◽  
High Calcium Concentration ◽  
Cellular Permeability

ABSTRACT Increasing the calcium concentration 5 times or more in the medium used for studying the inactivation of arginine-vasopressin by rat kidney medulla slices caused a marked inhibition of the inactivating activity of such slices. This effect was not found in homogenates of rat kidney medulla. The results are in agreement with the interpretation that the high calcium concentration decreased the cellular permeability to the hormone. This would seem to give a rational explanation of the vasopressin-resistant diabetes insipidus which is found in hypercalcaemia.

scholarly journals Secretion and degradation of parathormone as a function of intracellular maturation of hormone pools

1979 ◽  
Vol 83 (3) ◽  
pp. 521-528 ◽  
Author(s):  
JJ Morrissey ◽  
DV Cohn
Keyword(s):  
Cyclic Amp ◽  
Half Life ◽  
Calcium Concentration ◽  
Hormone Secretion ◽  
Ionized Calcium ◽  
Dibutyryl Cyclic Amp ◽  
Low Calcium ◽  
High Calcium ◽  
Parathormone Secretion

The biosynthesis, processing, and secretion of parthormone and the effect of calcium on these processes were measured in dispersed porcine parthyroid cells incubated with [(35)S]methionine. Proparathormone was detected at 10 min, the earliest time measured, and was rapidly and apparently quantitatively converted to parathormone. The half-life of the prohomormone pool was 15 min. Secretion of parathormone was detected by 20 min. In pulse-chase experiments there was a period between 20 and 40 min during which the wave of newly-synthesized parathormone was secreted. After 40 min during little additional radioactive hormone was secreted, but dibutyryl cyclic AMP, an agent that can mobilize stored parathormone, when added to the incubation mixtures enhanced radioactive parathormone secretion but only after 60 min, although it increased net hormone secretion as determined by radioimmunoassay to the same extent at all times studied. When the ionized calcium concentration of the medium was lowered, more radioactive hormone was secreted at all times but the effect was greatest on that hormone that was synthesized less than 60 min previously ; however, net hormone secretion in contrast to radioactive hormone was enhanced equally at all intervals. These data could mean that the refractoriness to secretion of parathormone 40-60 min of age was related to maturation of secretory container preparatory to storage. Low calcium (0.5 mM) stimulated hormone secretion up to fivefold compared to high calcium (3.0 mM) but did not affect synthesis of parathormone or proparathormne or conversion of the latter to hormone. During processing at least 70 percent of the intracellular parathormone was lost, presumably through proteolysis and this degradation was greater at high calcium. These data have been interpreted in light of the concept that two secretable pools of parathormone exist within the parathyroid.

Regulation of epithelial and lymphocyte cell adhesion by adenosine deaminase–CD26 interaction

2002 ◽  
Vol 361 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Silvia GINÉS ◽  
Marta MARIÑO ◽  
Josefa MALLOL ◽  
Enric I. CANELA ◽  
Chikao MORIMOTO ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Adhesion ◽  
T Cell ◽  
B Cells ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Surface ◽  
Adenosine Deaminase ◽  
Cell To Cell Adhesion ◽  
Lymphocyte Cell

The extra-enzymic function of cell-surface adenosine deaminase (ADA), an enzyme mainly localized in the cytosol but also found on the cell surface of monocytes, B cells and T cells, has lately been the subject of numerous studies. Cell-surface ADA is able to transduce co-stimulatory signals in T cells via its interaction with CD26, an integral membrane protein that acts as ADA-binding protein. The aim of the present study was to explore whether ADA—CD26 interaction plays a role in the adhesion of lymphocyte cells to human epithelial cells. To meet this aim, different lymphocyte cell lines (Jurkat and CEM T) expressing endogenous, or overexpressing human, CD26 protein were tested in adhesion assays to monolayers of colon adenocarcinoma human epithelial cells, Caco-2, which express high levels of cell-surface ADA. Interestingly, the adhesion of Jurkat and CEM T cells to a monolayer of Caco-2 cells was greatly dependent on CD26. An increase by 50% in the cell-to-cell adhesion was found in cells containing higher levels of CD26. Incubation with an anti-CD26 antibody raised against the ADA-binding site or with exogenous ADA resulted in a significant reduction (50–70%) of T-cell adhesion to monolayers of epithelial cells. The role of ADA—CD26 interaction in the lymphocyte—epithelial cell adhesion appears to be mediated by CD26 molecules that are not interacting with endogenous ADA (ADA-free CD26), since SKW6.4 (B cells) that express more cell-surface ADA showed lower adhesion than T cells. Adhesion stimulated by CD26 and ADA is mediated by T cell lymphocyte function-associated antigen. A role for ADA—CD26 interaction in cell-to-cell adhesion was confirmed further in integrin activation assays. FACS analysis revealed a higher expression of activated integrins on T cell lines in the presence of increasing amounts of exogenous ADA. Taken together, these results suggest that the ADA—CD26 interaction on the cell surface has a role in lymphocyte—epithelial cell adhesion.

Abscission in agriculture

1984 ◽  
Vol 13 (2) ◽  
pp. 97-103 ◽  
Author(s):  
Daphne J. Osborne
Keyword(s):  
Cell Adhesion ◽  
Natural Process ◽  
Citrus Fruits ◽  
Biochemical Mechanisms ◽  
Cell To Cell Adhesion

Abscission—the natural process by which cell-to-cell adhesion is lost at specific points in plants—plays an important role in the maturing and harvesting of many crops. Understanding of the biochemical mechanisms involved makes control of the abscission process possible and this has been put to practical use in agriculture: for example, in harvesting citrus fruits.

scholarly journals Integrated Analyses of miRNA and mRNA Profiles in Leukocytes and Serums in Traditional Chinese Medicine (TCM)-Defined Pi-qi-deficiency Syndrome and Pi-wei damp-heat Syndrome Resulting from Chronic Atrophic Gastritis

2020 ◽  
Author(s):  
Leiming You ◽  
Shen Zhang ◽  
Ting’an Li ◽  
Xiaopu Sang ◽  
Kunyu Li ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Collagen Type ◽  
Mirna Gene ◽  
Chronic Atrophic Gastritis ◽  
Deficiency Syndrome ◽  
Gene Interactions ◽  
Functional Changes ◽  
Neutrophil Degranulation ◽  
Cell To Cell Adhesion ◽  
Heat Syndrome

Abstract Background: To investigate the microRNA (miRNA)-gene interactions underlying leukocyte functions and characteristics, especially the potential serum biomarkers, implicated in the traditional Chinese medicine (TCM)-defined Pi-qi-deficiency syndrome (PQDS) and Pi-wei damp-heat syndrome (PDHS) resulting from chronic atrophic gastritis (CAG). Methods: Using RNA/miRNA-sequencing approach, we identified the syndrome-specific miRNAs and genes in leukocytes or serums, and further analyzed their functions and pathways to decode their potential roles in contributing to the characteristics and functions of leukocytes. Especially, we validated the syndrome (Zheng)-specific miRNA-gene interactions to explorer their roles for the characteristic and functional changes of leukocytes. Also, we evaluated the possibility of location of syndrome-specific miRNAs into plasma exosomes, and analyzed their validated targets to reveal their potential roles in the body.Results: Compared with healthy control population, we found that despite being the TCM-defined syndromes resulting from the same disease of CAG, the Zheng-specific genes and miRNAs were not same. The PDHS-specific leukocyte genes were mainly involved in defense and immune responses, and enriched in neutrophil degranulation and nucleotide-binding-oligomerisation-domains (NOD)-like receptor signaling pathways, as well as several synapses-related pathways. The expression upregulation of PDHS-specific genes enriched in the neutrophil degranulation pathway, indicated the enhanced leukocyte degranulation activation in the PDHS. The PQDS-specific genes in leukocytes were implicated in inflammatory response, extracellular matrix (ECM) organization and collagen catabolism. They could be enriched in mitogen-activated protein kinase (MAPK) signaling, IL17 signaling and helper T (Th) cell differentiation pathways, especially the pathways associated with cell-to-cell adhesion/junction and communication such as ECM-receptor interaction, cell adhesion molecules (CAM) and ECM organization, probably directly contributing to the characteristics and functions of leukocytes in the PQDS. Also, the experimentally-supported miRNA-gene interactions, concerned with the targets of COL4A2 (collagen, type IV, alpha 2), COL26A1 (collagen, type XXVI, alpha 1), SPP1 (secreted phosphoprotein 1) and PROCR (endothelial protein C receptor), were specifically implicated in the regulation of pathways related to cell-to-cell adhesion/junction and communication, suggesting the potential roles of the PQDS-specific miRNA-gene interactions for the characteristic and functional changes of leukocytes in the PQDS. Interestingly, the PQDS-specific miRNAs in the serums and the corresponding leukocytes, seemed to have the common roles in contributing to the characteristics and functions of leukocytes in the TCM-defined PQDS of CAG. Importantly, the hsa-miR-122-5p could be a potential biomarker candidate for the TCM-defined PQDS, capable of being contained and carried in plasma exosomes and especially much higher expression in both the leukocytes and corresponding serums in the CAG patients with PQDS rather than PDHS. Conclusions: These results may provide new insights into the characteristic and functional changes of leukocytes in the two TCM syndromes, PDHS and PQDS, especially the miRNA-mediated gene regulation underlying leukocyte characteristics and functions, with potential leukocyte and serum biomarkers for future application in integrative medicine.Trial registration: ClinicalTrials.gov, NCT02915393. Registered on September 17, 2016.

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