Intrathymic Gap Junction-Mediated Communication

1994 ◽  
pp. 155-158 ◽  
Author(s):  
Luiz A. Alves ◽  
Antonio C. Campos de Carvalho ◽  
L. Parreira-Martins ◽  
Mireille Dardenne ◽  
Wilson Savino
Keyword(s):  
Gap Junction ◽  
Mediated Communication

Potassium transfer assay for cell communication: effects of phorbol esters, retinoic acid, and furosemide

1991 ◽  
Vol 261 (6) ◽  
pp. C1115-C1122 ◽  
Author(s):  
M. L. Ledbetter ◽  
P. L. Medrek ◽  
B. M. Spinney
Keyword(s):  
Retinoic Acid ◽  
Gap Junction ◽  
Mass Culture ◽  
Phorbol Esters ◽  
Cell Communication ◽  
Ion Transfer ◽  
Mediated Communication ◽  
Human Diploid Fibroblasts ◽  
Communication Effects ◽  
State Content

Using a mass culture assay for the contact-dependent transfer of potassium among cells with intrinsic differences in ability to concentrate it, we have investigated the ability of several drugs to influence this form of cell communication. We concentrated on 12-O-tetradecanoylphorbol-13-acetate (TPA), which is known to interfere with gap junction-mediated communication and ion transport in several other systems, and compared its effects with those of its inactive derivative, 4-O-methyl-TPA. We found that the communication between mouse BALB/c 3T3 cells and human diploid fibroblasts was reduced in the presence of TPA but not O-methyl-TPA and that this inhibition was not obscured by small but measurable influences of TPA on steady-state content and transport of 86Rb+. We confirmed these findings using an autoradiographic assay for transfer of uridine derivatives among cells in contact. We also showed that retinoic acid had no effect on communication in the ion transfer assay but that furosemide, an inhibitor of Na(+)-K(+)-2Cl- cotransport, stimulated ion transfer dramatically both in the presence and absence of TPA. These results indicate both the promise and the limitations of the potassium transfer assay for identifying potential modulators of gap junction-mediated cell communication.

198 CILOSTAMIDE SUSTAINS GAP JUNCTION-MEDIATED COMMUNICATION AND CHROMATIN REMODELLING IN PIG OOCYTES

2012 ◽  
Vol 24 (1) ◽  
pp. 211
Author(s):  
C. Dieci ◽  
F. Franciosi ◽  
V. Lodde ◽  
I. Lagutina ◽  
I. Tessaro ◽  
...  
Keyword(s):  
Gap Junction ◽  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Culture Period ◽  
Control Group ◽  
Functional Coupling ◽  
Mediated Communication ◽  
Developmental Potential ◽  
Chromatin Configuration ◽  
Defined Culture

In the pig, the efficiency of in vitro embryo production procedures is still limited. It has been suggested that prematuration treatments could improve the developmental capability of oocytes. In particular, recent studies conducted in the bovine (Luciano, 2011, BOR, in press) indicate that the prolongation of a patent bidirectional crosstalk between the oocyte and the surrounding cumulus cells, together with the maintenance of a proper level of cAMP during the prematuration culture, could be beneficial to oocytes that have not yet acquired full meiotic and developmental capability. The aim of the present study was to assess the effect of treatment with cilostamide, an inhibitor of the phosphodiesterase 3 (PDE3), which degrades cAMP, on the functional status of gap junction-mediated communication (GJC) in pig cumulus–oocyte complexes (COC). Moreover, since chromatin configuration represents a marker of oocyte differentiation and competence, the effect of cilostamide on the process of chromatin remodeling was also evaluated during the culture period. To this aim, COC were collected from 3- to 6-mm antral follicles and cultured for up to 24 h in defined culture medium supplemented with 0.1 IU mL–1 of FSH in the presence or absence of 1 μM cilostamide. The GJC functionality was assessed by Lucifer Yellow fluorescent dye microinjection at the time of collection (0 h) and after 12, 18, or 24 h of culture. Chromatin configuration was evaluated by fluorescence microscopy after removal of cumulus cells and DNA staining with Hoechst and oocytes were classified according to Bui et al. (2004 BOR 70, 1843–1851) as SC, (with stringy chromatin within the germinal vesicle), GVI (with chromatin condensed in a rim around the nucleolus), GVII-IV (where the beginning of formation of chromatin strands is typical), ProMI (prometaphase I) and MI (metaphase I). The administration of cilostamide sustained functional coupling for up to 24 h of culture as the percentage of COC with open GJC was significantly higher when compared with the control group (62.2% vs 30%; P < 0.05) and not significantly different from the time 0 h (80%). The maintenance of the coupling during the culture period was accompanied by a delay of the meiotic resumption as only 26.3% of cilostamide-treated oocytes underwent germinal-vesicle breakdown and reached ProMI stage compared to the control group (62.1%; P < 0.05). Moreover the transition towards advanced stages of differentiation, as judged by the chromatin configuration, was slowed down in the presence of cilostamide. In conclusion, our study indicates that the maintenance of elevated cAMP levels through the inhibition of PDE3 sustains a functional bidirectional communication between the oocyte and cumulus cells and delays meiotic resumption in the pig oocyte. This could be a useful approach for the development of prematuration treatments aimed at improving the embryonic developmental potential of pig oocytes. Experiments are in progress in our laboratories to confirm this hypothesis. This study has been supported by EU FP6 grant n LSHB-CT-2006-037377 (Xenome) EU FP7- n°223485 (Plurisys).

scholarly journals The Sleep-inducing Lipid Oleamide Deconvolutes Gap Junction Communication and Calcium Wave Transmission in Glial Cells

1997 ◽  
Vol 139 (7) ◽  
pp. 1785-1792 ◽  
Author(s):  
Xiaojun Guan ◽  
Benjamin F. Cravatt ◽  
George R. Ehring ◽  
James E. Hall ◽  
Dale L. Boger ◽  
...  
Keyword(s):  
Gap Junction ◽  
Glial Cells ◽  
Wave Transmission ◽  
Calcium Wave ◽  
Mediated Communication ◽  
Gap Junctional Communication ◽  
Gap Junction Communication ◽  
Junctional Communication ◽  
Nervous System Function ◽  
Gap Junctional

Oleamide is a sleep-inducing lipid originally isolated from the cerebrospinal fluid of sleep-deprived cats. Oleamide was found to potently and selectively inactivate gap junction–mediated communication between rat glial cells. In contrast, oleamide had no effect on mechanically stimulated calcium wave transmission in this same cell type. Other chemical compounds traditionally used as inhibitors of gap junctional communication, like heptanol and 18β-glycyrrhetinic acid, blocked not only gap junctional communication but also intercellular calcium signaling. Given the central role for intercellular small molecule and electrical signaling in central nervous system function, oleamide- induced inactivation of glial cell gap junction channels may serve to regulate communication between brain cells, and in doing so, may influence higher order neuronal events like sleep induction.

Cell-, age- and stage-dependent distribution of connexin43 gap junctions in testes

1992 ◽  
Vol 103 (1) ◽  
pp. 81-96
Author(s):  
M.S. Risley ◽  
I.P. Tan ◽  
C. Roy ◽  
J.C. Saez
Keyword(s):  
Gap Junctions ◽  
Gap Junction ◽  
Indirect Immunofluorescence ◽  
Sertoli Cells ◽  
Leydig Cells ◽  
Cell Types ◽  
Immunogold Electron Microscopy ◽  
Mediated Communication ◽  
Surface Distribution ◽  
Occluding Junctions

Immunocytochemical data demonstrate that the distribution of gap junction connexin43 (Cx43) in rodent testes is dependent on cell type, testis maturation, and stage of the mature seminiferous epithelium. Western blotting and indirect immunofluorescence microscopy using anti-peptide antisera to Cx43 revealed abundant Cx43 in rat and mouse testes and mouse TM3 and TM4 cells. Cx43 mRNA was detected in rat testes and mouse TM4 cells by Northern blot analysis. Cx43 was localized by immunogold electron microscopy to gap junctions on Sertoli cells and Leydig cells. A punctate distribution of Cx43 was observed on peritubular cell surfaces following indirect immunofluorescence of detergent-permeabilized tubule segments. In cryosections from testes of immature (to 30 days) rats, and mature rats and mice, Leydig cells showed a punctate surface distribution of Cx43 following indirect immunofluorescence. A diffuse cytoplasmic fluorescence was also seen in spermatocytes and spermatogonia. Cx43 staining associated with Sertoli cells was age- and stage-dependent. Over 90% of the tubules in immature tests (22-30 days) contained Cx43 in the region of Sertoli-Sertoli occluding junctions and in the adluminal compartment. In mature rat testes, however, Cx43 immunostaining was detected in only 60% of 1195 tubule sections where it was abundant proximal to the Sertoli cell occluding junctions. All strongly stained tubules were from stages I-VIII, while negatively stained tubules were at stages IX-XIV. Cx43 immunostaining in mature mouse testes was also stage-dependent with all positive tubules at stages VI-VIII. In contrast to Cx43, Cx26 and Cx32 were detected by immunofluorescence only in the apical regions of the seminiferous epithelia in 90% of tubules from mature rats. Consistent with the observed Cx43 immunostaining, octanol-sensitive in situ dye-coupling was observed between Leydig cells, between peritubular cells and between Sertoli cells, suggesting the occurrence of functional gap junctions in these cell types. These observations provide evidence for extensive gap junction-mediated communication between a variety of testis cell types important to the support of spermatogenesis.

scholarly journals Natriuretic Peptide Precursor C Delays Meiotic Resumption and Sustains Gap Junction-Mediated Communication in Bovine Cumulus-Enclosed Oocytes1

2014 ◽  
Vol 91 (3) ◽  
Author(s):  
Federica Franciosi ◽  
Giovanni Coticchio ◽  
Valentina Lodde ◽  
Irene Tessaro ◽  
Silvia C. Modina ◽  
...  
Keyword(s):  
Gap Junction ◽  
Natriuretic Peptide ◽  
Mediated Communication ◽  
Peptide Precursor

Gap-junction-mediated Communication in Human Periodontal Ligament Cells

2013 ◽  
Vol 92 (7) ◽  
pp. 635-640 ◽  
Author(s):  
R. Kato ◽  
Y. Ishihara ◽  
N. Kawanabe ◽  
K. Sumiyoshi ◽  
Y. Yoshikawa ◽  
...  
Keyword(s):  
Gap Junction ◽  
Periodontal Ligament ◽  
Periodontal Ligament Cells ◽  
Mediated Communication ◽  
Human Periodontal Ligament Cells

Gap-junction-mediated Communication in Human Periodontal Ligament Cells

2014 ◽  
Vol 73 (4) ◽  
pp. 111-112
Author(s):  
Ryushi Kato ◽  
Yoshihito Ishihara ◽  
Noriaki Kawanabe ◽  
Kumi Sumiyoshi ◽  
Yusuke Yoshikawa ◽  
...  
Keyword(s):  
Gap Junction ◽  
Periodontal Ligament ◽  
Periodontal Ligament Cells ◽  
Mediated Communication ◽  
Human Periodontal Ligament Cells

Persistence of gap junction communication during myocardial ischemia

2001 ◽  
Vol 280 (6) ◽  
pp. H2563-H2571 ◽  
Author(s):  
Marisol Ruiz-Meana ◽  
David Garcia-Dorado ◽  
Sinead Lane ◽  
Pilar Pina ◽  
Javier Inserte ◽  
...  
Keyword(s):  
Myocardial Ischemia ◽  
Gap Junction ◽  
Lucifer Yellow ◽  
Electrical Coupling ◽  
Atp Depletion ◽  
Mediated Communication ◽  
Rat Cardiomyocytes ◽  
Adult Rat ◽  
Gap Junction Communication ◽  
Chemical Coupling

During myocardial ischemia, severe ATP depletion induces rigor contracture followed by intracellular Ca2+ concentration ([Ca2+]i) rise and progressive impairment of gap junction (GJ)-mediated electrical coupling. Our objective was to investigate whether chemical coupling through GJ allows propagation of rigor in cardiomyocytes and whether it persists after rigor development. In end-to-end connected adult rat cardiomyocytes submitted to simulated ischemia the interval between rigor onset was 3.7 ± 0.7 s, and subsequent [Ca2+]i rise was virtually identical in both cells, whereas in nonconnected cell pairs the interval was 71 ± 12 s and the rate of [Ca2+]i rise was highly variable. The GJ blocker 18α-glycyrrhetinic acid increased the interval between rigor onset and the differences in [Ca2+]i between connected cells. Transfer of Lucifer yellow demonstrated GJ permeability 10 min after rigor onset in connected cell pairs, and 30 min after rigor onset in isolated rat hearts submitted to nonflow ischemia but was abolished after 2 h of ischemia. GJ-mediated communication allows propagation of rigor in ischemic myocytes and persists after rigor development despite acidosis and increased [Ca2+]i.

scholarly journals Gap Junction Channels of Innexins and Connexins: Relations and Computational Perspectives

2019 ◽  
Vol 20 (10) ◽  
pp. 2476 ◽  
Author(s):  
Alejandro Sánchez ◽  
Carlos Castro ◽  
Dora-Luz Flores ◽  
Everardo Gutiérrez ◽  
Pierre Baldi
Keyword(s):  
Gap Junction ◽  
Cell Communication ◽  
Machine Learning Techniques ◽  
Computational Techniques ◽  
Tissue Formation ◽  
Clinical Tool ◽  
Mediated Communication ◽  
Gap Junction Channels ◽  
Learning Techniques ◽  
Cell Propagation

Gap junction (GJ) channels in invertebrates have been used to understand cell-to-cell communication in vertebrates. GJs are a common form of intercellular communication channels which connect the cytoplasm of adjacent cells. Dysregulation and structural alteration of the gap junction-mediated communication have been proven to be associated with a myriad of symptoms and tissue-specific pathologies. Animal models relying on the invertebrate nervous system have exposed a relationship between GJs and the formation of electrical synapses during embryogenesis and adulthood. The modulation of GJs as a therapeutic and clinical tool may eventually provide an alternative for treating tissue formation-related diseases and cell propagation. This review concerns the similarities between Hirudo medicinalis innexins and human connexins from nucleotide and protein sequence level perspectives. It also sets forth evidence of computational techniques applied to the study of proteins, sequences, and molecular dynamics. Furthermore, we propose machine learning techniques as a method that could be used to study protein structure, gap junction inhibition, metabolism, and drug development.

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